The Champion Submarine-Killing Submarine of World War Two


Second War Patrol

Back to Main

Area off the Southeast Coast of Shikoku
February 22 - April 15, 1944

(A) Prologue
Arrived Midway from first war patrol on 30 January, 1944, and commenced refit. No major items of repair were required and no alternations were undertaken. This vessel was assigned to Commander Submarine Division 61 for administration, refit, and training. Officers and crew were quartered at the Submarine Base Recreation Center for rest and recreation until 12 February, 1944, when they moved back aboard and took over from the relief crew. Upon inspection the ship was found to be in excellent condition and the refit very satisfactorily completed. The Commanding Officer desires to take this opportunity to commend the officers and men of Subdiv 61 relief crew for a job well done.

The period 13 to 15 February, 1944, was spent in making preparations for underway training. Two men wre transferred to the hospital and replacements were received from Subdiv 61. Two officers were also temporarily detached to the hospital at Pearl Harbor - Ensign O.A. Morgan, U.S.N., with probable hernia, and Lt.(jg) J.F. Byrum, U.S.N.R., as the result of a fractured foot incurred during the recreational period. Two replacement officers, Lt.(jg) J.E. Morris, U.S.N.R. and Ensign J.L. From, U.S.N., reported on board for duty. In addition, J.J. Morin, CMM, U.S.N., received an appointment to the rank of Warrant Machinist for temporary duty and was retained on board.

On 16 February, 1944, this vessel conducted independent underway operations which included tests of all machinery, exercises at diving stations, emergency drills, and a dive to 406 feet to test for leaks.

The period 17 to 18 February inclusive was spent in underway training operations with Commander Submarine Division 61 on board as training officer. On the first day three zed and three radar rehearsals were made on a screened target. During the evening conducted radar tracking exercise and four night radar rehearsal runs on single target. On the second day conducted one zed rehearsal, on radar rehearsal, two zed firing runs, and one radar firing run. All three exercise torpedoes ran straight, hot, and normal and resulted in hits on the target, which was screened.

The period 19 to 21 February, 1944 was spent in final loading and preparations for sea. Readiness for sea date 22 February, 1944
(B) Narrative
22 February
1558(Y) Departed Midway for Area six (ABLE) at two engine speed. Using constant helm zigzag plan. Had aircraft escort until sunset
23 February
Enroute patrol area at standard speed on two engines.
0800(Y) Changed to east longitude time and date.
25 February
Enroute patrol area at two engine speed.
1600(M) Set clocks back one hours to Zone -11 time.
1616(L) Sighted what appeared to be aviator's life raft on port beam. Changed course to investigate and found it to be a large barnacle-covered log.
26 February
Enroute patrol area at two engine speed. Using constant helm zig-zag plan during daylight. During forenoon barometer started dropping and sea picked up considerably, but was forced to slow only slightly. Still making about ten knots on two engines.
27 February
Enroute patrol area at two engine speed. Moderate sea running, but getting no worse.
0654(L) SD radar contact on very peculiarly shaped cumulous cloud. Sky was absolutely clear in all directions except to the northwest where the peculiar brown colored thunderhead appeared. Pips on radar appeared at about three mile intervals between 14 and 25 miles and were essentially stationary. Pips gradually disappeared as we entered the rain squall. Sea abating somewhat during evening.
28 February
Enroute patrol area at two engine speed.
0835(L) Submerged for trim dive and to water batteries and routine torpedoes. Considerable work was required on two torpedoes which had Midway sand in the charge and check valves. Operated TDC and gyro angle setters thoroughly and cleaned all contacts.
0900(L) Set clocks back one hour to minus ten zone time.
1330(K) Surfaced and continued toward area at two engine speed.
29 February
Enroute patrol area at two engine speed. During early morning hours barometer started falling rapidly and wind and sea picked up considerably.
0631(K) Forced to slow to two-thirds speed because of heavy seas. Discovered the fresh water hose had gotten adrift from its reel in the superstructure forward and about ten feet of it had snaked out through a limber hole. Unable to remedy the situation until the seas subside. It is out of the question to put a man on deck. During the evening the wind has subsided, but the sea is still rather heavy. Am able to make about seven and one-half knots.
1 March
Enroute patrol area at two engine speed. Suring early morning hours seas gradually subsided allowing increased speed.
1215(K) Put two men on deck to remove fresh water hose. Had to cut it clear and heave it overboard. Job just completed and men climbing up to bridge when at - -
1332(K) SD radar contact at 22 miles. (Aircraft contact #1.)
1233(K) Submerged to avoid detection, although plane was not sighted. Routined torpedoes and went to 410 feet to test for leaks.
1443(K) Surfaced and continued toward patrol area at two engine speed.
2230(K) Increased speed to maximum on two engines in order to arrive near area as soon as possible. Could make very little more on three engines in the present sea.
2 March
Enroute patrol area at best two engine speed.
0100(K) Barometer started falling and wind and sea increasing in intensity.
0421(K) SJ radar contact at 40,000 yds. moving rapidly across screen. Disappeared at 18,000 yds. Believed to be a low-flying airplane, but many possibly have been interference from electrical equipment on board. (Aircraft contact #2.)
1135(K) Barometer has dropped .62 inches in the last few hours with a full gale blowing and very heavy seas. Nearly lost a lookout overboard so slowed to 2/3 speed. Held on as long as possible in order to reach the area west of the Southern Islands by tomorrow afternoon, but in this sea it is simply impossible. We have rolled as much as 40 several times during the day and at anything over 2/3 speed the pounding is pretty bad. All day long visibility has varied between 500 and 8000 yds, with rain most of the time.
1700(K) Barometer started rising slowly, but there is very little change in wind or sea. During the day the wind and sea have hauled around from South to North-north-west. The hull of this boat is supposed to be considerably stiffer than its predecessors, but an interesting item has come to light during the day. With the hull hogging and sagging in the heavy seas the hull ventilation lines in the forward battery strain and creak at the flanged unions. One such union even pulled away slightly. It appears to me that the hull is quite a lot more flexible than is commonly believed. At any rate it is a comforting thought.
3 March
Enroute patrol area at 2/3 speed. Wind and sea abating gradually and barometer rising.
1343(K) Increased speed to standard on two engines.
1600(K) Set clocks back one hour to minus 9 zone time. Sea is now quite calm compared to what it has been.
1855(I) Increase speed to best two engine speed. Should enter area sometime tomorrow, depending on whether or not we are allowed to remain on the surface. Expect to pass Sumisu Shima and Tori Shima about 2300 tonight.
2250(I) Passed Sumisu Shima abeam to stbd. distant 28 miles.
4 March
Enroute patrol area at two engine speed.
0900(I) The body of one "good" Jap floated by close aboard to port still wearing a life preserver. Did not attempt search of body because of obvious state of decomposition.
0922(I) Entered area 6 (ABLE) at Lat. 31-03.5N.
0930(I) Slowed to patrol speed of 6 knots on one main engine. Changed course to head for south central portion of area where our contacts were made on last patrol.
1200(I) Submerged to routine torpedoes and to make repairs to the T.D.C. and SJ radar. Both T.D.C. and SJ have been operating unsatisfactorily for the past twenty-four hours. Conducting periscope patrol in calm sea.
1810(I) Surfaced to conduct surface patrol. T.D.C. still out of commission. SJ radar functioning, but not normally. Wind and sea picking up from SSE with falling barometer.
2237(I) TDC back in commission. All test problems check correctly. Barometer still falling rapidly and wind and sea increasing. All indications point to an approaching typhoon.
5 March
Conducting surface patrol across area in the face of an oncoming typhoon. Altered course as much as permissible to pass around to southward of typhoon center.
0400(I) Barometer h it low of 29.32" with wind of 60 to 70 knots and violent seas. Lying to headed up into the sea although making turns for six knots. Complete overcast with intermittent squalls throughout the night and early morning. Secured after lookout to prevent losing him overboard. Continued surface patrol throughout the day with heavy seas and slowly rising barometer. Visibility variable and sky completely overcast. Heading for southwestern corner of area to clear storm area and investigate Bungo Suido-Saipan traffic route.
2200(I) Barometer now stands at 29.96" with wind of about 15 knots and heavy sea from NNW which apprears to be subsiding. According to all available information typhoons are supposed to be very infrequent in this area at this time of year, but we were welcomed by one on our very first night in the area. From its apparent path I should judge that a few roofs are missing in Tokyo by now.
6 March
Conducting surface patrol in heavy seas toward southwestern corner of area. Seas gradually subsiding.
0755(I) Altered course to northward to patrol along western area boundary. Continued surface patrol throughout the day in reduced visibility ranging from 8 to 10 thousand yards. Seas continued to be fairly heavy with fresh breeze from WNW.
1700(I) Changed course to eastward to patrol back across area. Intend to make general search of area before concentrating at any particular point. I believe the enemy is constantly shifting his convoy routes and a general search should locate them. Will have to dive tomorrow in order to routine torpedoes as it is entirely too rough to do it on the surface. SJ radar is again functioning normally after shifting back to the old tubes that had been taken out.
7 March
Conducting surface patrol to the eastward across area. Moderately heavy sea running.
0810(I) Sky overcast and visibility about ten thousand yards because of haze of fog. Submerged to routine torpedoes and because of visibility. Conducting periscope patrol to the eastward across Kobe-Palau traffic route.
1818(I) Surfaced in rather heavy seas and commenced surface patrol to eastward toward Kobe-Saipan traffic route. Visibility still low with wind of 18 to 20 knots and intermittent showers.
8 March
Conducting surface patrol to eastward toward Kobe-Saipan traffic route. Moderately heavy sea from WNW. Sky overcast with intermittent showers.
1128(I) Body of dead Jap floated by about 50 feet to port. Dressed in dark khaki-colored trousers and white undershirt with no life jacket. The last body we saw was dressed in Japanese Army uniform and had on a "Mae West" type life jacket. Its position was to the northeast of our present position and in this vicinity there is a southwesterly set. Looks like someone got a transport around here, quite possibly one of the two ships we sank in this area last patrol, one of which was a cargo-transport. Both bodies had apparently been in the water for a considerable time. Continued surface patrol in relatively poor visibility with partially overcast sky. Sea still rather heavy with fresh breeze from WNW.
1600(I) Altered course to northward to patrol up along Kobe-Saipan route. We have now completely crossed the area twice without making a contact of any description. Undoubtedly all small-craft have been kept in port because of the weather, which has also been very poor for flying . Am determined to maintain surface patrol as much as possible except for dives to routine torpedoes and rest the lookouts.
9 March
Conducting surface patrol to northward along Kobe-Saipan traffic route. Moderately heavy sea from WNW. Sky overcast most of the time.
0600(I) Altered course to westward to patrol back across area in search of convoy lanes.
1302(I) Submerged for trim dive and to routine torpedoes. Sky has been completely overcast all day, but sea has abated considerably. Conducting periscope patrol.
1820(I) Surfaced and continued surface patrol to westward. Sea now quite calm, but sky is completely overcast.
10 March
Conducting surface patrol to westward across area in search of convoy lanes. Sea calm, but sky completely overcast, obscuring a full moon.
0145(I) SJ radar out of commission.
0330(I) SJ radar back in commission on ship's A.C. Radar M-G set undergoing repairs.
1300(I) Altered course to northward along western area boundary. Visibility low, varying between 2,000 and 8,000 yards all morning. Sky overcast with frequent rain squalls and one hail storm. Low clouds with frequent thunder and lightning which caused considerable disturbance on SD radar.
1600(I) Changed course to eastward to patrol back across area in search of convoy lanes. During the evening the weather cleared with only partially overcast sky.
11 March
Conducting surface patrol to eastward across area. Partially cloudy with full moon and moderate sea. During early morning hours wind and sea picked up from WNW with completely overcast sky. During morning watch visibility was reduced to as little as 1000 yards. We had rain, hail, sleet, and snow storms, all within the space of four hours. By noon the sea was quite heavy and continually getting worse. By now I'm convinced that this is the breeding place of all the bad weather found in the North Pacific Ocean at this time of year. Since arriving in the area we've had one day that could be called fair. It was bad enough here last patrol, but this time even the Japs are keeping clear of it. To date we have seen nothing except two Jap corpses.
1232(I) Submerged to routine torpedoes, water batteries, and work on SJ radar motor-generator. Had to mount generator armature in lathe and take a cut on the armature. Tried all afternoon to conduct periscope patrol, and did so - anywhere between 25 and 150 feet.
1823(I) Surfaced heading into seas which were a good forty feet from crest to trough. Blew all MBT's practically dry with HP air. Continued surface patrol to NW heading into seas. Making good one-half knot although making turns for seven knots. Sky overcast with variable visibility. It would be impossible to make a successful torpedo attack in such weather. Even if you could see the target and close it you'd have to set the torpedoes to run at about 25 feet.
12 March
Conducting surface patrol to northwestward in heavy seas. During morning watch wind and sea abated somewhat.
0700(I) Altered course to westward toward northwestern corner of area. By mid-afternoon wind and sea were moderate with good visibility, although the sky was still almost completely overcast. Continued surface patrol.
13 March
Conducting surface patrol to westward toward northwestern corner of area. Sea moderate and sky partially cloudy with bright moonlight.
0506(I) SJ radar out of commission. Radar motor-generator is still out of commission also, although repairs are nearly completed. Considerable difficulty has been experienced with the SJ since leaving Midway for patrol.
0800(I) Altered course to southeastward to patrol along Bungo Suido - Saipan traffic route.
1300(I) Submerged to routine torpedoes and work on SJ radar.
1450(I) Secured gyro compass follow-up system for cleaning. Conducting periscope patrol.
1702(I) Gyro compass and SJ radar back in commission, including radar motor-generator.
1824(I) Surfaced and continued patrol tosoutheastward along Bungo Suido - Saipan route. Sea calm with overcast sky and continual rainfall. Visibility very poor.
14 March
Conducting surface patrol to southeastward along Bungo Suido - Saipan traffic route. Sea calm with cloudy sky. Sky clearing toward morning.
1118(I) Sighted patrol plane bearing 037 T, distant eight miles. Plane was flying very low and was not picked up on SD radar. (Aircraft contact #3.)
1119(I) Submerged to avoid detection and changed course to eastward. Conducting periscope patrol. Decided to remain submerged while closing approximate track of plane in hope that he was searching ahead of an enemy convoy. Routined torpedoes.
1200(I) Altered course to northeastward to close Kobe-Palau traffic route.
1829(I) Surfaced and continued surface patrol to northeastward, angling across Kobe-Palau route. Sea relatively calm with partially overcast sky. Our first plane contact in the area was made on the first day that we've had decent flying weather and appears to substantiate the contention that this area is well patrolled by aircraft as was found on our last patrol here. After eleven days in the area we still have had no surface craft contacts. It is hoped, however, that the improved weather will induce the enemy to venture out of port. In the meantime we have been making every effort to have a crew of men who are 100% "Qualified in submarines." With the probable exception of two men making their first patrol, I'm sure we will attain our goal.
15 March
Conducting surface patrol to northeastward across Kobe-Palau traffic route. Sea calm with partially overcast sky.
0600(I) Altered course to southeastward to patrol vicinity of contacts made on last patrol.
1400(I) Sky completely overcast, but visibility is still good. Continued surface patrol.
2000(I) Altered course to northeastward to cover area between lanes and to arrive on Kobe-Saipan route by tomorrow night. Still no contacts of any description.
16 March
Conducting surface patrol to northeastward across area. Sea calm with partially overcast sky and intermittent rainfall. By daybreak sky was completely overcast, but remained on surface to extend area of search.
1000(I) SD radar contact at 26 miles moving in rapidly. (Aircraft contact #4.)
1001(I) Submerged to avoid detection, plane at 22 miles when radar was secured. Remained submerged to routine torpedoes and because of overcast sky. Conducting periscope patrol.
1830(I) Surfaced and continued patrol to northeastward to arrive on Kobe-Saipan traffic route at northern extremity of area. Sea calm and sky clear to partly cloudy.
2200(I) Arrived on Kobe-Saipan route and altered course to southeastward to patrol along this route. All contacts still confined to aircraft. It appears plausible that the Japs are routing most of their shipping along the coast or southward near the islands of the Nanpo Shoto in order to avail themselves of land-based air coverage and the protection of defensive mine fields. The total absence of sampans is not consistent with the observations made during our last patrol in this area.
17 March
Conducting surface patrol to southeastward along Kobe-Saipan traffic route. Sea calm an sky partially cloudy. A careful analysis of probable traffic routes, with most probably positions and times of interception, has been worked out assuming an average convoy speed of seven to nine knots along base course and utilizing all available information concerning times of arrival and departure from ports and course changes before sunrise and after sunset. A lack of contacts persists in spite of this analysis. In an effort to attain the best area coverage possible the following measures are being taken.

(1) Maximum permissible amount of surface cruising, using high periscope lookout
(2) General area coverage on both east-west courses and north-south courses prior to concentrating at any particular point.
(3) Investigation of areas lying between normal traffic lanes as well as "shortest-distance" routes.
(4) Concentration at points shown by analysis as mentioned above to be located as follows:
(a) Southbound convoys enroute Bungo Suido or Kobe to Palau or Saipan - crossing area during darkness - daylight position between Lats. 30 N and 30-30 N and between Longs. 134 E and 136 E.
(b) Northbound convoys enroute Saipan or Palau to Kobe or Bungo Suido - crossing area during darkness - daylight position between Lats. 31-30 N and 32 N and between Longs. 133-30 E and 135 E.
(5) In view of area limitations and probable air coverage during daylight it is considered most feasible to concentrate in the area described under 4(a) above so as to allow either submerged attacks on northbound convoys at dusk or night surface attacks, and either day or night surface chases and attacks on southbound convoys. It is also considered advantageous to patrol southward during daylight and northward at night.

It is hoped that adoption of the foregoing measures will result in contacts with the enemy. Continued surface patrol during daylight, although during the afternoon the sky became overcast and by evening there was a continual downpour with reduced visibility and a falling barometer.
2000(I) Altered course to westward along southern area boundary. Intend to start patrolling near the intersection of the Bungo Suido-Saipan and Kobe-Palau routes. By now have completely covered the area in all directions in a general surface patrol with only two aircraft contacts and no surface vessel contacts. With only fifteen more days remaining in which to patrol I believe it is advisable to start concentration at most likely positions.
18 March
Conducting surface patrol to westward along southern area boundary. Continual rainfall with low visibility and falling barometer. Sea is picking up considerably from the southeast. Wind of 15 to 20 knots from southeast, which is not a good sign. During early morning hours wind hauled around to the SW and increased in intensity with accompanying heavy seas. Remained on surface during daylight in complete overcast and continual downpour. Was forced to use SJ radar all day because of poor visibility. By 1600(I) the barometer had reached a low of 29.49 with a wind of 55 to 60 knots which had hauled around to NNW. Seas very heavy. Numerous waterspouts with the wind very gusty and a confused sea.
1640(I) Passed through the center of a typhoon of moderate intensity. Thereafter the barometer started rising and the wind dying down. Sea still very heavy, but apparently moderating somewhat.
2000(I) Changed course to northwestward so as to head more into the sea. Have not had a good star fix for 48 hours. After fifteen days in the area with no contacts I am seriously considering sending an information dispatch to Comsubpac in the hope I may be assigned a more productive area. Have decided, however, to hold off a few more days, as an accurate DF of my position would undoubtedly result in rerouting any traffic which may be passing through the area in the near future. I am almost positive that I have not disclosed my presence to date.
19 March
Conducting surface patrol to northwestward in heavy seas and poor visibility. Wind and sea slowly abating with rising barometer. Will have to dive sometime today for trim and routining of torpedoes. To date, after 25 days on patrol, have spent only 4 2/3 days submerged, and that time was required to avoid planes, check trim, and routine torpedoes. Believe a destroyer could get away with patrolling this area this time.
0802(I) Submerged for trim dive, routining of torpedoes, work on main engines and SJ radar, and to rest the lookouts. Heavy sea running with partially overcast sky. Conducting periscope patrol.
0807(I) Altered course to northward.
1838(I) Surfaced in moderate sea and commenced surface patrol to southeastward. Sky clear.
2241(I) SJ radar contact bearing 150 T, distant 3,250 yards. Small pip and nothing visible from the bridge. Concluded it was a small sampan so maneuvered to avoid. While turning range closed to about 2000 yards, but nothing was sighted although it was very clear and dark. (Ship contact #1.)
2246(I) Sighted flare-up light on sampan and made out very dim outline of small boat. Range 3,850 yards.
2249(I) Lost radar contact at 5,400 yds. Do not believe that our presence was detected.
20 March
Conducting surface patrol to southeastward toward south central part of area. Am going to patrol this general vicinity for two or three days as it appears to be the most likely point for interception of shipping.
0242(I) Sighted lights of two sampans about a mile apart bearing 180 T and 195 T, distant about six thousand yards. Could not pick up on radar. Maneuvered to avoid on the surface. (Ship contact #2.)
0630(I) Arrived on Kobe-Palau traffic route and altered course to southward to patrol that line.
1019(I) SD contact at 16 miles. Submerged to avoid detection. (Aircraft contact #5.) Plane was not sighted as the sky was partially overcast with low clouds. Conducting periscope patrol to southward. Visibility good, but wind and sea increased in intensity throughout the day. Watered battery.
1817(I) Altered course to westward.
1826(I) Surfaced in heavy seas with wind of about 30 knots. Continued surface patrol to westward.
2016(I) SJ contact bearing 110 T, distant 3,900 yds. Very small pip which disappeared in two minutes.
2020(I) Sighed light of sampan bearing 155 T, distant about 3000 yds. (Ship contact #3.) Believe these to have been two separate sampans as the heavy sea made it impossible to see the light at much over 3,000 yards. Could not pick up second sampan on radar.
2023(I) Lost light of sampan from view bearing 130 T. Continued surface patrol to westward. After 16 days in the area with only two plane contacts have sighted five sampans and contacted a plane in the last twenty hours. Am remaining in this vicinity in the hope that the sampans are being used as observers, since this is not a likely fishing ground and the sampans have been distributed along a line corresponding to the Bungo Suido-Saipan route, but about 15 to 20 miles to the northeastward. Such an offset routing would allow a sharp course change just before sunrise for southbound convoys and the same changed just after sunset for northbound convoys. This observation checks with our observations during our last patrol in this area. During he evening watch the wind has decreased to about 16 knots and there is a moderately heavy sea fro WNW which appears to be abating. Barometer is holding steady.
21 March
Conducting surface patrol to westward in moderately heavy seas. Partially overcast sky.
0800(I) Altered course to southeastward to patrol across Bungo Suido - Saipan traffic route. Continued surface patrol during daylight in good visibility although sky was about 70% overcast most of the time.
1819(I) Arrived on Kobe - Palau line and altered course to northeastward.
2056(I) Sighted light bearing 155 T, distant about five thousand yards. No contact on the radar. (Ship contact #4.)
2100(I) Made out light to be that of a sampan. Maneuvered to avoid on the surface.
2151(I) Sighted light bearing 147 T, distant about five thousand yards. (Ship contact #5.) Could not pick up on radar. Do not believe this was the same sampan previously sighted as the other appeared to be making way to the westward and they usually operate in pairs. Maneuvered to avoid on the surface.

It has proven very difficult to pick up sampans on the radar except at short ranges in very calm sea. On very dark nights, such as we're having at present, it is quite possible to get close enough to them to be detected before seeing them. The lights carried, if any are carried, are very dim and low and cannot be seen very far in a rough sea. It is always quite possible, as we found on our last patrol here, that they are serving as "bait" for a darkened patrol vessel nearby. From their plotted positions it is very probably that we have been contacting the same two sampans during the past twenty-five hours. I have purposely remained in their general vicinity in hope of contacting something larger.

Continuing surface patrol to northeastward to clear area of sampan contacts as it is very probable that we have been detected, although there has been no positive evidence of such being the case as yet.
22 March
Conducting surface patrol to northeastward in moderate sea. Sky partially cloudy, but visibility is good, although there is no moon.
0600(I) Altered course to southeastward. Continued surface patrol in variable cloudiness with occasional showers. Kept SJ radar manned whenever visibility was reduced because of rainfall.
2000(I) Altered course to northeastward. Wind and sea have moderated throughout the day. Sky partially cloudy with good visibility.
23 March
Conducting surface patrol to northeastward across area. Will be forced to dive today for trim and routining of torpedoes. The gyro compass is sticking somewhat and will be decommissioned for cleaning. Intend to patrol back across area to the westward along the northern area boundary tonight and tomorrow.
0801(I) Very flat sea and overcast sky so submerged and commenced periscope patrol to northwestward toward northern area boundary. Routined torpedoes, cleaned and repaired gyro compass, and worked on SJ radar.
1005(I) Heard the first of a series of twenty-five depth charges dropped at irregular intervals up to 1112(I). The charges were a long distance off, estimated at fifteen to twenty miles, and it was impossible to tell for sure from which direction the sound came. Could see nothing at any time, although the sea was calm and a very high periscope watch was maintained.
1528(I) Sighted fishing sampan dead ahead on opposite course, distant eighteen hundred to two thousand yards. Only one mast, which was aft and very low. Shortly thereafter picked up his screws. (Ship contact #6.) Was forced to do some fancy maneuvering to prevent his catching a Batfish as he suddenly decided to lay his net across our bow and in a long arc at a fairly high speed. Had a good look at him at about 500 yard range and am convinced he was an innocent, though troublesome, fisherman, without radio and unarmed. Was tempted to eliminate him, but could not feel justified in taking a chance on disclosing our presence. The net he laid was marked by eighteen bamboo poles carrying white flags, which were of considerable help in avoiding it.
1600(I) Resumed periscope patrol to northwestward.
1831(I) Surfaced and commenced surface patrol to westward across area near northern area boundary. Making standard speed on two engines. Have found it necessary to occasionally put a good load on the engines in order to eliminate accumulated lube oil which causes excessive smoking when a lot of power is needed on short notice. Only have nine more days in the area and still have 60,000 gals. of fuel remaining so intend to start suing some of it in wider area coverage.
2315(I) Altered course to southwestward.
24 March
Conducting surface patrol at standard speed on two engines to southwestward toward western area boundary.
0802(I) Submerged on southerly course in neutral zone to westward of area. Conducting periscope patrol.
1200(I) Altered course to westward. During the afternoon watch the sea picked up considerably from WNW. Wind of about 20 knots.
1850(I) Surfaced in moderately heave sea. Star fix showed us to be nineteen miles inside eastern boundary of Area 8 and about forty-five miles west of our own area. We had an excellent star fix prior to submerging this morning. Average current during the day was 1 3/4 knots setting WSW. Commenced surface patrol to southeastward toward southwestern corner of our own area.
2200(I) Altered course to eastward.
2345(I) Arrived in assigned area.
2400(I) Altered course to southeastward.
25 March
Conducting surface patrol to southeastward just inside western area boundary. Sea moderately heavy from WNW with good visibility and variable cloudiness.
0730(I) Altered course to eastward along southern area boundary.
1348(I) SD contact at 20 miles, moving in. (Aircraft contact #6.)
1349(I) Submerged with plane at 18 miles to avoid detection. Routined torpedoes while submerged and overhauled Bendix log. Periscope patrol.
1830(I) Surfaced in calm sea and overcast sky. Continued surface patrol to eastward. Intend to patrol northward along Nageya - Palau line tomorrow.
2202(I) Altered course to northwestward, and increased speed to standard on two engines.
26 March
Conducting surface patrol to northwest ward at best two engine speed. Intend to conduct submerged patrol on Bungo Suido - Saipan line today.
0756(I) Sighted two-masted sampan of about thirty tons bearing 304 T, distant 8 miles, on approximate course 090 T. Changed course to maintain range while sampan was carefully studied through high periscope. (Ship contact #7.)
0803(I) Submerged and altered course to westward.
0900(I) Altered course to northwestward to patrol along Bungo Suido - Saipan route. Conducting periscope patrol in oily sea and good visibility.
1803(I) Altered course to northwestward.
1842(I) Surfaced just outside western area boundary and commenced surface patrol to northeastward. Sea glassy with a low haze hanging over water.
2300(I) Altered course to eastward to patrol along northern area boundary toward Kobe - Palau traffic route.
27 March
Conducting surface patrol to eastward along northern area boundary.
0200(I) Barometer started falling, with overcast sky and glassy sea. Looks like we're in for some more bad weather.
0602(I) Altered course to southward. Barometer still falling and wind and sea picking up from SE.
0824(I) Sighted sampan bearing 194 T, distant 8 miles, on easterly course. Avoided on the surface. He may also have sighted us because he changed course away from us while were were turning. (Ship contact #8.)
0930(I) Resumed patrol to south southeastward. Frequent rain squalls with reduced visibility.
1516(I) Sighted two-masted sampan bearing 176 T, distant about 6 miles, on approximate course 320. Avoided on the surface and do not believe we were sighted. (Ship contact #9.)
1609(I) Resumed patrol to south southeastward. Sea has picked up considerably with a wind from SSE of about 20 knots. Barometer still falling with overcast sky and intermittent rainfall.
2206(I) Altered course to southwestward. Moderately heavy sea running and continual rainfall. Wind hauling to SSW and increasing in intensity. Barometer still falling.
28 March
Conducting surface patrol to southwestward near southern area boundary. Barometer 29.53 with moderately heavy sea and wind of about thirty knots from SW. Visibility very low because of overcast and intermittent rainfall.
0300(I) Altered course to westward along southern area boundary.
0617(I) Altered course to southwestward as morning fix showed a marked northwesterly set during the night.
0700(I) Barometer hit low of 29.47. Sea heavy and wind of 30 to 40 knots. During remainder of day the barometer rose slowly, but wind and sea remained about the same, although veering around to WNW. Visibility variable with frequent rain squalls necessitating use of SJ radar during part of the day.
1500(I) Altered course to northeastward to patrol along Bungo Suido - Saipan traffic route.
1830(I) During evening twilight lookout sighted two masts bearing 325 T, distant about 7,000 yards. (Ship contact #10.) Could not pick up on radar and it was too dark to see through the periscope. Both C.O. and Executive Officer sighted it, but were unable to make sure whether it was a sampan, submarine, or a small patrol boat. If it was a submarine it had either a periscope or radar mast extended, but should easily have been picked up on the radar. Lookout who first sighted it reported two masts. Darkness prevented any further observations and as nothing could be picked up on sound or radar decided to maneuver to avoid. Sea still very heavy from WNW.
2000(I) Continued surface patrol to northwestward along Bungo Suido - Saipan route. Barometer has steadied at 29.73 with wind of about 20 knots and heavy sea. Sky partly cloudy with fair to good visibility.
29 March
Conducting surface patrol to northwestward along Bugo Suido - Saipan traffic route. With only four days remaining in which to patrol the area and still having contacted nothing except planes and sampans am pretty well convinced that traffic is being routed closer to the islands of the Nanpo and Nansei Shotos than heretofore. Even the aircraft patrol is light. We have been driven down only four times by planes during twenty-five days on station. Surface patrol during daylight has been maintained at a maximum consistent with the demands of maintaining trim, routining torpedoes in heavy seas, and making necessary material repairs. Although we won't have given up hope until we're moored to our base, we are all somewhat discouraged at our lack of success. The morale problem is being solved by plenty of hard work toward qualification of new men, and in this at least, we have been most successful.
1100(I) Altered course to eastward.
1208(I) Submerged for trim dive, routining of torpedoes, and to make repairs to the SJ radar. Conducting periscope patrol.
1840(I) Surfaced in calm sea and continued patrol to eastward. Sky partly cloudy with good visibility. Have had a lot of trouble with the SJ radar this patrol, including the radar motor generator, but have managed to keep it operating at critical times by continuous effort on the part of radar personnel.
30 March
Conducting surface patrol to eastward across north central portion of area. Moderate sea with good visibility although barometer has started dropping again.
0050(I) Sighted two lighted sampans bearing 060 T and 070 T, range 7,900 yards. Picked up by SJ radar when coached on the bearing, but lost again at 8,300 yds. Maneuvered to avoid on the surface. (Ship contact #11.)
0115(I) Continued surface patrol to eastward.
0309(I) Sighted two lighted sampans bearing 040 T. Radar picked them up at 6,400 yards, but lost them again at 7,300 yards. Maneuvered to avoid on the surface. (Ship contact #12.)
0330(I) Continued surface patrol to eastward. Wind and sea increased in force throughout the day with falling barometer, but toward evening began to subside an barometer to rise again. Intermittent rainfall with reduced visibility required considerable use of the SJ radar during daylight.
0900(I) Altered course to southeastward to patrol Kobe - Saipan route.
2300(I) Altered course to northward to patrol Nagoya - Palau route.
31 March
Conducting surface patrol to northward along Nagoy - Palau traffic route. Fair visibility with moderate sea running.
1600(I) Altered course to southwestward upon reaching northern area limit.
2110(I) Altered course to southeastward to patrol along Kobe - Saipan traffic route. Sea calming down with very little wind and good visibility.
1 April
Conducting surface patrol to southeastward along Kobe - Saipan traffic route. This is our last day in the area. Have decided to delay in sending a departure message until tomorrow night when I will not be so apt to embarrass the submarine operating to eastward of me in case I am D-F'd. There is also a chance of making contact with the enemy while enroute through the Nanpo Shoto. Am certainly envious of the boat which reported contacting a nineteen ship convoy. Since we couldn't be there, too, I wish I could have given him my torpedoes.
0400(I) Altered course to northward near eastern area boundary.
0800(I) Altered course to northeastward. Morning fix showed considerable westerly set during the night. Sea calm and sky clear except for slight haze.
0838(I) Received message from Comsubpac directing us to remain an additional day on station and attempt interception of BB reported by submarine to southward. Altered course to westward at three engine speed. Can only intercept if I'm allowed to remain on the surface. Had intended diving for trim and routining of torpedoes today, but will skip the dive and routine torpedoes on the surface tonight if it remains fairly calm.
2000(I) Slowed to best two engine speed to conserve fuel. Will be able to intercept at this speed. Routined all torpedoes in tubes and reloads during the night. Check over entire fire control system and overhauled one tube firing valve.
2 April
Making best two engine speed to westward to attempt interception of BB about fifty miles to eastward of Tanega Shima. Should arrive on his tract at 0500(I) this morning. Encountering continuously rainy weather with very poor visibility. Sky completely overcast with falling barometer and rising wind and sea. Water is highly phosphorescent and the wake we're leaving could be seen for some distance.
0500(I) Rain ceased, but the sky was still completely overcast and it was impossible to obtain a navigational fix. Slowed to patrol speed of five knots and altered course to southward. Believe we are on the track of the target. Have taken best estimates of current into consideration.
0511(I) Submerged to conduct periscope patrol. Sky cleared completely during the day and se was moderate until about 1600(I), when wind increased considerably. No sight or sound contacts of any description were made. Visibility was very good.
1855(I) Surfaced in moderately heavy sea. Star fix verified our position. We had patrolled the desired line during the day in spite of the fact that we had been unable to obtain a morning fix. Set course to eastward at two engine speed across areas 8 and 6A in order to depart area 6A at specified position. After today's lack of results I'm about convinced that our luck just isn't in this patrol.
3 April
Enroute across area at two engine speed toward departure point. Barometer very unsteady with wind and sea increasing considerably.
0000(I) Increased speed to three engine speed.
1705(I) Departed area 6(A) at Latitude 31-32'N enroute Midway. Wind and sea moderate from NW and barometer rising slowly. Should pass Bayonnaise Rks. abeam to port about 0300(I) tomorrow morning.
4 April
Enroute Midway from patrol area at three engine speed.
0148(I) SJ radar contact on Sumisu Shima bearing 142 T, distant 31,500 yards.
0225(I) Sighted Sumisu Shima bearing 174 T, distant 23,400 yards.
0316(I) Lost radar contact on Sumisu Shima bearing 221 T, distant 35,400 yards.
0955(I) Lookout sighted low-flying patrol plane bearing 327 T, distant seven miles. (Aircraft contact #7.) Plane was not picked up on SD radar.
0956(I) Submerged to avoid detection. Bow buoyancy vent would not close hydraulically, but was closed by hand. Decided to remain submerged to work on the vent and to routine torpedoes. We have had quite a bit of trouble with bow buoyancy vent operating sluggishly for some time. Succeeded in getting the vent operating satisfactorily for the time being. Decided to patrol here submerged for the rest of the afternoon on chance of making a contact. Am reluctant to go home empty handed.
1224(I) Heard distant explosion which may have been a bomb or depth charge, but was barely audible. Nothing in sight through periscope.
1258(I) Heard two more distant explosions.
1600(I) Set clocks ahead one hour to minus ten zone time. Conducting periscope patrol.
1907(K) Surfaced in moderate sea and set course for Midway at three engine speed.
2155(K) After some difficulty due to interference, transmitted my 0410000.
2316(K) Transmitter secured, message having been receipted for.
5 April
Enroute patrol area to Midway at three engine speed. Wind and sea moderating considerably. Sky cloudy to completely overcast, but visibility good.
6 April
Enroute Midway at three engine speed.
0800(K) Slowed to two engine speed to conserve fuel.
1124(K) Lookout sighted patrol plane bearing 155 T, distant six miles, on approximately parallel course and flying low. (Aircraft contact #8.) Did not pick up on radar. Submerged to avoid detection.
1334(K) Surfaced and resumed course for Midway at two engine speed.
7 April
Enroute Midway at two engine speed.
1600(K) Set clocks ahead one hour to minus eleven zone time. Weather partly cloudy, sea moderate, with very bright moonlight at night.
8 April
Enroute Midway at two engine speed. Sea moderate with partly cloudy sky.
9 April
Enroute Midway at two engine speed. Sea moderate with variable cloudiness.
1517(L) Transmitted my 090300.
1606(L) Transmitter secured, the message having been receipted for.
10 April
Enroute Midway at two engine speed. Wind and sea picking up from SE. Sky nearly completely overcast, but visibility is good most of the time
0546(L) Radar interference on SD radar which lasted all day. Probably from POLLACK.
0647(L) Forced to alter course radically to avoid ramming large whale.
1600(L) Set clocks ahead one hour to minus twelve zone time.
2359(M) Changed to west longitude time and date.
10 April
Enroute Midway at two engine speed. Wind and sea moderate with fair visibility.
0458(Y) Encountered light fog with visibility of less than 1000 yards.
1420(Y) Commanding Officer held formal inspection of the ship.
1644(Y) Secured from inspection.
11 April
Enroute Midway at two engine speed. Sea calm, but visibility poor due to high fog.
0220(Y) Fog closed in.
0225(Y) Fog lifted.
0345(Y) Altered courses to southward toward rendezvous with Midway escort.
0547(Y) SD contact at six miles on escort planes.
0600(Y) Went ahead full speed on four main engines using wide constant helm zigzag toward Midway. Various planes contacted visually and by radar.
0645(Y) Picked up Midway on SJ radar bearing 105 T, distant 28,000 yards.
0809(Y) Pilot came aboard.
0855(Y) Moored alongside submarine dock at Midway.
0920(Y) Commenced fueling ship and unloading torpedoes. Left twenty-two torpedoes at Midway. Commenced repairs to #1 M.B.T. salvage line which was discovered to be cracked, allowing the tank to flood.
1130(Y) Completed fueling, took 23,140 gals.
1330(Y) Completed unloading torpedoes, one torpedo left fwd. and one aft.
1610(Y) Completed repairs to #1 M.B.T. salvage line. Underway for Pearl Harbor at four engine speed. Plane escort until sunset.
12 April
Enroute Pearl Harbor at four engine speed.
13 April
Enroute Pearl Harbor at four engine speed.
1600(Y) Set all clocks ahead one hour to plus eleven zone time.
14 April
Enroute Pearl Harbor at four engine speed.
1600(X) Set all clocks ahead one and one-half hours to plus nine and one-half zone time.
15 April
Enroute Pearl Harbor at four engine speed.
0000(V-W) Slowed to three engine speed.
0630(V-W) Contacted PC 602 at rendezvous and proceeded in company with escort to Pearl.
1100(V-W) Moored at Submarine Base, P.H., T.H.
(C) Weather
A detailed analysis of the weather encountered during the patrol, viewed from the standpoint of visibility and sea conditions, forms the basis for the following interesting tabulation
---Weather Conditions---
Fair Poor Very Poor Typhoon
Enroute Area 6 2 1 1
In area 6A 13 13 3 2
Enroute Midway 8 1 0 0
Total days 27 16 4 3
No accounting is made of cloud conditions in the above as most of the so-called "fair" days were partly cloudy to completely overcast. During the "poor" days it was often necessary to use the SJ radar during daylight to extend the area of search. There was noticeable improvement in the weather during the later part of the patrol, probably due to the seasonal shift of the monsoons.
(D) Tidal Information
Currents encountered in the area were, in general, as described in "Sailing Directions for Japan - Volume II, 1943", with the exception that a strong westerly set of 1 knot or more was noted on two occasions near the western area boundary.

Current conditions were much more irregular that found on our previous patrol in this area, and were subject to considerable variation with changes in local weather conditions.

On our return passage through the Nanpo Shoto a very marked southerly set was noticed between Bayonnaise Rocks and Sumisu Shima.
(E) Navigational Aids.
Celestial navigation was employed exclusively.

The only landfall made was on the island of Sumisu Shima while enroute Midway from the area. This island was picked up by SJ radar at a ranged of 31,000 yards and contact maintained out to 35,000 yards. It was sighed visually at a range of 23,400 yards in fair moonlight.
(F) Ship Contacts
No. Time
Type(s) Initial
1 2241(I)
19 Mar.
1 Sampan
(Showed Light)
3,250 yds. - - - SJ Radar 3,250 yds Did not sight from bridge except for flare-up light. Lost contact at 5,400 yds. Very small pip.
2 0242(I)
20 Mar.
2 Sampans
6,000 yds. (Est) - - - Visually by O.O.D. and lookout Sampans were about a mile apart and carrying lights. At no time were we about to pick them up on radar.
3 2016(I)
20 Mar.
2 Sampans
 (one lighted)
3,900 yds. - - - 1 by SJ Radar, 1 visually Sampans were about a mile apart. Picked up only one by radar, but saw the light of the other. Lost radar contact almost immediately.
4 2056(I)
21 Mar.
1 Sampan
5,000 yds. - - - Visually by lookout Four minutes after sighting light, saw the boat itself. Never could pick up on the radar.
5 2151(I)
21 Mar.
1 Sampan
5,000 yds. - - - Visually by lookout Could not pick up on radar. Believed to be different boat from contact #4 as they seem to operate in pairs.
6 1528(I)
21 Mar.
1 Sampan
 (15 to 25 tons)
1,800 yds 150 T
8 kn
Periscope by O.O.D. Sampan was on opposite course. Laid net almost around us with eighteen flag markers. Obviously a fisherman.
7 0706(I)
26 Mar.
1 Sampan
 (2 masts)
8 mi. 090 T
8 kn
Periscope on surface Sighted through periscope while patrolling on the surface. Two masts, probably for radio antenna.
8 0824(I)
27 Mar.
1 Sampan
 (1 mast)
8 mi. 110 T
8 kn
Periscope on surface May have sighted us also becuse he turned away while we were turing to avoid him.
9 1516(I)
27 Mar.
1 Sampan
 (2 masts)
8 mi. 320T Visually by lookout Avoided on surface. Similar to contact #7 with probably radio. We were not detected.
10 1830(I) 30-13N
1 Sampan
(2 masts)
7,000 yds. 185T Visually by lookout Evening twilight. Might possibly have bee a submarine or small patrol boat, but could not pick up on radar.
11 0050(I)
30 Mar.
2 Sampans
7,900 yds. Est. NW Visually by lookout Radar picked up sampans when coached on the proper bearing. Very small pip at 7,900 yards. Lost again at 8,300 yards.
12 0309(I)
30 Mar.
2 Sampans
8,000 yds. Est. NW Visually by lookout Radar picked up sampans at 6,400 yds. and lost again at 7,300 yds. Not believed to be the same as contact #11.
(G) Aircraft Contacts
No. Time
Type(s) Initial
1 1232(K)
1 Mar.
Unknown 22 mi. --- Radar 22 mi. Plane not sighted - dived on contact.
2 0421(K)
2 Mar.
Unknown 20 mi. --- SJ Radar, 40,000 Yds Pip moved rapidly across PPI screen and disappeared at 9 miles
3 1118(I)
14 Mar.
Patrol Bomber 8 mi. --- Visually by J.O.O.D. Plane sighted while taking h igh periscope sweep on surface; also seen from the bridge by O.O.D.
4 1000(I)
16 Mar.
Unknown 26 mi. --- Radar 26 mi. Plane not sighted, but closed rapidly from 26 to 22 miles
5 1019(I)
20 Mar.
Unknown 16 mi. --- Radar 16 mi. Plane not sighted. Sky partially overcast with low clouds
6 1348(I)
25 Mar.
Unknown 20 mi. --- Radar 20 mi. Plane not sighted. Sky partially overcast. Dived when range had decreased to 18 miles.
7 0955(I)
4 April
Patrol Bomber 7 mi. SE Visually by lookout Plane flying very low and could not be detected by radar.
8 1124(K)
6 April
Patrol Bomber
(4 engines)
6 mi. ENE Visually by lookout Plane flying low and could not be detected by radar.

NOTE: Friendly aircraft contacted in vicinity of Midway and Pearl Harbor on return voyage are not included in the above.

(H) Attack Data
No contacts with suitable targets were made and no attacks conducted.
(I) Mines
No mines were carried on this patrol and no enemy mines encountered.
(J) Anti-Submarine Measures and Evasive Tactics.
No enemy anti-submarine measures were encountered except for occasional plane patrols and a considerable number of sampans which are probably used as observer fishermen. Some of the sampans were obviously equipped with radio, but nearly all carried lights at night.

Out of four planes encountered in the area, all in daylight, three were flying high enough to be detected by radar, while the fourth was flying low and was sighted from the bridge. Lack of traffic through the area probably accounts for the scarcity of planes.

Of the four planes encountered enroute to and from the area - only one was at night, and it was flying low enough to be detected by SJ radar. One other was detected by radar and the other two visually only, as they were flying very low.

The only evasive tactics employed were submergence to avoid detection by planes and surface maneuvering, both day and night, to avoid sampans. At no time was there any evidence of our having been detected while in the area.
(K) Major Defects and Damage.
No major defects were discovered to exist and no damage was sustained. Minor defects noted are being incorporated in tender work lists for correction during refit.
(L) Radio
Communication conditions were much the same as those which existed during he previous patrol in this area. Haiku's new frequency, 6380 Kcs., proved to be a worthwhile addition and prevented our missing several numbers during periods when other bands were excessively noisy. With the selection of bands now available, Haiku reception is on the whole quite satisfactory, except for natural or enemy interference. Fortunately BATFISH encountered very little of either during her second war patrol. By paralleling two frequencies this interference was minimized. All bands faded during the period 1800-2100 GCT, but cold be copied. The stand-by frequency, 56 Kcs., was not received west of Midway. Longitude 152 E. marked the extremity of usefulness for 16.68 Kcs. The one exception to the last statement was that very weak signals were heard one day while submerged at periscope depth in the patrol area. Less than 5% of the Haiku numbers were missed, all of these being missed while submerged. No messages were sent or received on the area frequency, 450 Kcs. No Comsubpac serials were missed. Unusual difficulty was encountered in transmitting BATFISH 041000 of April, in that there was considerable interference on 847 Kcs. The message was finally cleared on 8470 Kcs., however, after failure to raise NPM on 4235 Kcs. A memo including tabulated data on signal strength of all frequencies is being furnished the Force Communications Officer separately.
(M) Radar
The radar equipment in use on this vessel is all of the newest type. The equipment was inoperative only two and one-half hours during the patrol, but nevertheless a large number of circuit failures were encountered. The more important ones are listed:

a. Two cases of failure of 5U4G rectifier tubes in "B" regulated rectifier.
b. Failure of regulated rectifier voltmeter on the control unit.
c. Intermittent failure and trouble with motor-generator set.
d. Failure of resister R 44 in intensifier power supply of PPI causing an open circuit
e. Jamming of inner conductor of crystal disconnect unit in the contact position.
f. Failure of V(1)6, 6x5 tube, in the transmitter-receiver.
g. Failure of V2, 6AG7, in the PPI sweep circuit.
h. Burning away of coating on PPI cathode ray tube, V8, necessitating replacement
i. Failure of the IF tube receiver-indicator (6AC7)

On the SJ-1 Midway Island was tracked out to 34,000 yards. Rain squall contacts were obtained up to 20,000 yards. A contact was made on Sumisu Shima Rock at 32,000 yards. The range was decreased to 23,000 yards, then increased, with contact being finally lost at 35,400 yards. The pip was well defined and of strength E-1 to E-2. An accurate bearing was difficult to determine except inside 25,000 yards when lobe switching was used. At 25,000 yards a smaller pip was observed next to the main pip, probably from a nearby rock.

SJ-1 contact on sampans could not be counted on in moderately heavy seas, although good contacts were made up to 9,000 yards on sampans, with a smooth sea. Our boat's wake was detected on a smooth sea, and on one occasion it is believed a school of large fish was detected at ranges varying around 1000 yards.

The SJ-1 was observed to cause interference (random noise) on the RAK and RAl communication receivers, but this only during the daytime.

Normal search was conducted on the PPI 40,000 yard sweep, with added observation of the PPI 8,000 yard sweep and the A scope expanded sweep every 5 minutes.

No foreign radars were detected by the SJ-1, and there was no indication of DFing.

The transmitter-receiver, CW-43AAF-1, and in particular the magnetron, appeared to operate very satisfactorily.

SD-2 Performance.

The SD-2 operated satisfactorily with frequency meter tuning and routine maintenance. The thermal overload relay in S202 (plate voltage switch) occasionally kicked out at normal voltages.

Plane contacts were invariably made at ranges varying from 15 to 25 mils except for two occasions when planes estimated at 2 altitude were spotted from the bridge. Thunderclouds were picked up once at ranges varying from 12 to 20 miles.

The SD-2 was operated intermittently, being keyed on for 8 seconds in every 30 seconds by a switch lashed in series with the plate voltage switch.

No foreign radar interference was ever noticed, but occasional thunder and rain storms caused violent agitation of the SD-2 screen. This was often accompanied by arcing the antenna, and a display of St. Elmo's fire.
(N) Sound Gear and Sound Conditions
The lack of enemy ship contacts forestalls a detailed report on sound conditions in this area. The only sound contact on a ship was obtained at an estimated range of 2500 yards on a sampan. Only his screws were heard. Contact was made on both QB and JP. No other contacts were made, except for the usual fish. The lack of thermal gradients indicates good sound conditions.

A recurrent case of reduced sensitivity in the JK-QC receiver-amplifier, present since November 1943, was not remedied in Midway during refit there. A possible replacement at Sub Base Pearl Harbor is indicated. Other sound gear performs satisfactorily.
(O) Density Layers
From 1 March, 1944 to 6 April, 1944, eighteen bathythermograph cards were taken. No temperature gradients were encountered in area 6A. Water temperature varied only slightly. During the entire period no temperature below 65 F or above 67 F was recorded.

The following are characteristic readings:
Date Time Lat. Long. Depth Amt. of Change Remarks
3/1/44 0925 GCT 3158'N 15139'E 410 ft. None Taken enroute to area
3/11/44 0923 GCT 3122'N 13553'E 140 ft. None Isothermal at 66 F
4/3/44 0955 GCT 3020'N 13221'E 120 ft. -2 Taken in area 8.
The card taken in area 8 indicated a sharp 2 negative gradient at 100 ft. During the days submerged cruising, it also indicated a 2 increase at 100 ft.

All cards are being forwarded to the Chief of Naval Operations in accordance with current instructions.
(P) Health, Food, and Habitability
The health of officers and crew during the patrol was excellent, there being no sick days. This may be attributed, in part at least, to the comfortable temperatures encountered and the large amount of surface cruising employed. The usual number of minor complaints such as cuts or minor burns were experienced. One officer developed a rather painful case of "wisdom tooth" trouble, but fortunately that occurred on the way home.

In spite of considerable effort on the part of the cooks, the food on this patrol was not up to the standard set on our last. This decline is attributed to the lack of variety and poorer quality of stores received at Midway. The rice and part of the cereals received were found to contain weevils, while the Navy beans were moldy. In addition, the eggs were so old as to be almost unpalatable.

The boat was very comfortable at all times, both surface and submerged. The one item of habitability which needs improving is the method of elimination of odors from the sanitary tank inboard vents. No replacement filters were available at Midway, the lack of which resulted inconsiderable unpleasantness after a few weeks at sea. This subject is being referred to the tender force for correction during refit.
(Q) Personnel
The performance of duty of both officers and men during the patrol left nothing to be desired. In spite of a very uninteresting and unproductive patrol, morale remained high throughout. All hands seemed to hang onto their hopes of making an enemy contact right up to the time of entering Midway. It is believed that the maintenance of morale can be attributed to the many hours devoted to qualifying new men and in material upkeep. No advancements in rating were effected as all eligible men were advanced just prior t the start of the patrol. A summary of personnel status follows:

(a) Number of men on board during patrol: 72
(b) Number of men qualified at start of patrol: 49
(c) Number of men qualified at end of patrol: 69
(d) Number of unqualified men making their first patrol: 3
(e) Number of men advanced in rating: 0

In addition to the foregoing, one officer is being recommended for the designation "Qualified to command submarines". Three other officers completed their qualification notebooks during the patrol and one warrant officer is being recommended for promotion to Ensign.
(R) Miles Steamed - Fuel Used.
Midway to Area 6A 2,354 miles 23,380 Gals.
In Area 6A 3,941 miles 29,250 Gals.
Area 6A to Midway 2,347 miles 28,900 Gals.
Midway to Pearl Harbor 1,247 miles 24,820 Gals.
Total 9,889 miles 106,350 Gals.
(S) Duration
Days enroute to area (from Midway) 10
Days in area 31
Days enroute to base (to Pearl) 13
Days submerged 11
(T) Factors of Endurance Remaining
Torpedoes Fuel Provisions Personal Factor
24 11,141 Gals (Arrival Midway) 15 days 10 days
Limiting factor this patrol: Terminated by Operation Order. Two additional days were spent in this and adjacent area.
(U) Remarks
In the opinion of the Commanding Officer the lack of success on this patrol must bee attributed to the nearly complete absence of enemy traffic through the area. At no time were there any indications of merchant shipping having passed through the area. On four occasions attempts were made to intercept men-of-war, none of which were successful. In two of these instances the targets were submarines. It is believed that deviations from the supposed tracks, or schedules, caused failure of the other two attempts on surface craft. In spite of difficulties due to weather, our navigational position was pretty accurately determined in each case. 

Anti-submarine measures were noticeably lacking and it was possible to conduct most of the patrol on the surface. Dives were made only to check trim, routine torpedoes, and to avoid planes. It is felt that the area was thoroughly searched in as systematic a manner as was practicable. It is believed that the enemy is routing traffic both to the eastward along the islands of the Nanpo Shoto and to the westward near the coast of Kyushu in order to avail himself of the protection of land-based aircraft and defensive mine fields.

The decision of the Commanding Officer not to ask for a more productive area was influenced by our planned fleet attack on Palau, and nearby islands, which I hoped would result in combatant ships passing through the area enroute to, or from, the main islands of Japan. The decision was also based on prospects occasioned by two contact reports received earlier.

At the present time I feel that the area can be covered sufficiently well by submarines enroute to and from other areas as to justify elimination of it as an area patrolled continuously by one submarine.
Torpedoes fired: 0 Number of hits: 0
Ships sunk: 0 Ships sunk (Official): 0
Tonnage: 0 Tonnage (Official): 0
This patrol was designated as not successful for the Combat Insignia Award