//IMMEDIATE//

From: CDR Greg Turner (USS Grouper)
ComSubRon 12A
To: ComSubPac
Date: February 22,1943
Re: Patrol Format (May 01 - Cycle 2)

RMKS/ 1. Departed Pearl Harbor on 2 February 1943 and arrived in my assigned patrol area nine days later on 11 February 1943 in the late afternoon. Had aboard 24 Mk-14 Steam torpedos.

RMKS/ 2. 23:05 SJ radar picked up a contact bearing 254` at 12,500 yds and I closed its position. At 23:14 lookouts spotted a Shiratsuyu class Destroyer bearing 355` at 4,980 yds and I dove to periscope depth. A look through the scope then revealed 2 - Kuma light Cruiser's and an additional DD heading northwest at 25 kts. Sound reported at least 5 escorts in the area but I only spotted the two. After a quick setup at 23:22 fired 3 torpedos at the Cruiser at 2,100 yds with a depth of 10 feet. Moments after firing the one torpedo prematured and alerted the Task Force, which made an immediate turn to port and evaded my torpedos. I dove for 350 feet as sonar reported several DD's closing on our position. We successfully evaded a determined counterattack and by 00:47 had slipped clear of the DD's which dropped a total of 48 depth charges in their attack. None of the charges were to close but did shake the boat around a bit. Arrived at periscope depth at 00:51 and could not see anything due to darkness but sound reported the DD's were still searching astern of our position. I continued out of the area and completed reloading the tubes. Surfaced at 01:40 and commenced charging the batteries while heading east. Dove to radar depth as the sun rose.

RMKS/ 3. Friday Feb 12,1943, 14:37 SJ contact bearing253` at 14,260 yds. Headed for at full speed. At 15:05 I spotted 2 ships bearing from 068` to 072` at 9,300 yds and identified 1 - Troop Ship and 1 - Large Freighter making 6.6 kts. I crossed their track about 2,200 yds ahead and setup for a stern shot. At firing time the Freighter turned to port so I setup on the Troop ship and at 15:43 fired 2 torpedoes at it at 555 yds (SUNK). I then turned hard to starboard to get a shot at the Freighter. The Freighter had slowed to under 6 kts and at flank speed I was making 6.8 kts slowly closing the distance. At 15:59 I had closed to 571 yds off the Freighters starboard beam and fired 2 torpedoes at it (SUNK). The Freighter fired on my periscope but missed and then digested my 2 torpedoes and went down in under 9 minutes. After this action my soundman reported that the second torpedo had struck the ship but failed to detonate. I came to radar depth and cleared the area to the southeast.

RMKS/ 4. Surfaced at 17:25 and at 19:03 sound reported low speed screws bearing 034` and SJ radar gave the range at 13,400 yds. I set an intercept course and at 19:25 the starboard lookout made visual on a Tanker at 5,357 yds. Over the next few minutes we sighted a total of 2 -Armed Merchants, 1-Tanker, 1-Large Freighter and 1-Troop ship. Went to periscope depth at 19:15 and worked into firing position. At 19:38 fired 1 torpedo at the Tanker at 512 yds (DUD). Immediately fired a 2nd fish at the Tanker at 640 yds (DUD). Fired a 3rd fish at the Tanker at 830 yds (DUD). At 19:40 I shifted to the Freighter and fired 1 Torpedo at it at 760 yds (DUD) then turned to bring the stern tubes to bear. At 19:43 fired a 4th torpedo at the Tanker at 1,732 yds (DUD). Then I shifted to the Armed Merchant and fired 1 torpedo at it at 730 yds, which detonated and caused the ship to slow only slightly. I then fired a 2nd torpedo at the Armed Merchant at 620 yds (DUD). At 19:44 fired a 3rd torpedo at the Armed Merchant (DUD). With the battery being dangerously low and the torpedoes failing to work I broke off the attack to clear the area to charge and check my remaining torpedoes for problems. At 19:38 I surfaced after loosing visibility on the convoy and headed east to trail while charging and reloading. Lookouts spotted the Troop ship by itself and I ordered a surface gun action on it. At 20:19 opened fire with the deck gun at 1,281 yds. Over the next few minutes the gun crew fired 33 rounds for 29 hits and 3 misses that sank the ship (SUNK). At this time the XO reported that we had lost use of Engine 2 and DC Motor 3 and the SD Radar due to mechanical failures and they would have to be repaired in port. We had handled such breakdowns before so it didn't hinder us very much.

RMKS/ 5. At 23:14 SJ Radar reported a contact bearing 313` at 13,410 yds and one minute later I dove to radar depth about 6,000 yds ahead of the contact. At a range of 4,800 yds I identified 1 - Nagato Battleship and to my excitement 1 - Yamato class Battleship. Making 23.3 kts. I went ahead flank to try and get in firing position and as luck would have it at 23:22 the Task Force turned in my direction. I slowed to 1/3 and setup to fire all bow tubes. At 23:27 as the Yamato passed ahead at 1,100 yds I fired all six tubes set for20 feet and then dove. I had only spotted 1 - DD but sound reported several in the area. 20 seconds from impact one torpedo prematured and over the next few moments sound reported hearing 2 - Dud hits and 3 - detonations on target but no breaking up noise. Sound reported that the BB slowed but continued on. After arriving at 350 feet I turned to trail while completing the reload forward of my one remaining torpedo. With only 3 torpedo remaining (1-Fwd, 2 -Aft) I continued to trail. Came to radar depth at 00:31 and picked up a contact bearing 179` at 11,230 yds and one at 188` at 8,140 yds. I tried to end around but a Destroyer appeared out of the dark and drove me under. After passing us over the DD reversed course and charged down our port side dropping 6 depth charges. The resulting damage was to the Forward Torpedo Room Hull-Moderate, Officers Quarters Hull-Moderate, Bow Planes-Minor, and Engine 3-Moderate. With all this happening I didn't stop the dive until we hit 366 feet. Eased back up to 325 to relieve a little pressure and by 01:36 the hull breach in the Officers Quarters had been repaired but the XO reported that the Forward Torpedo Room and Forward Battery was taking on water. Damage control had the leak secured in the Forward Torpedo Room by 01:34 and the flooding stopped as the pumps began to gain head way. Sound reported the DD heading away so I went to radar depth and picked it up bearing170` at 7,390 yds. I turned away from the DD and started to open out. At 01:41 I surfaced and speed away at flank speed. By 02:30 the Bow Planes and Engine 3 were repaired and we continued our patrol.

RMKS/ 6. Dove to radar depth at 06:59 as the sun rose. At 12:43 made SJ contact bearing 310` at 13,930 yds. Identified 1 - Fubuki DD and 4 other ships yet unidentifiable. Continued to close and at 13:39 identified 6 - Troop ships and 2 - Supply ships. At 13:46 fired 1 torpedo at the 2nd troop ship at 990 yds (DUD). Fired a 2nd torpedo at the same ship at 880 yds (DUD). Turned to use the bow tube and at 13:51 fired1 torpedo at the third Troop ship at 1,100 (DUD) then dove deep. The escorting DD didn't make contact on me and the whole convoy speed away to the southwest. Lost sonar contact at 14:05 and went to radar depth where I spotted a DD 5,700 yds astern. I observed this DD until losing visual on it at 14:51 then surfaced and set course for Pearl Harbor.

Patrol Summary:

TDC: Auto

Conditions:
Seas: Moderate
Weather: Mostly Cloudy

Enemy Sunk:

1. Feb 12,1943, 15:43, Troop Ship,      (9,510 tons), 32-22N x 134-47E
2. Feb 12,1943, 16:00, Large Freighter, (4,280 tons), 32-23N x 134-46E
3. Feb 12,1943, 20:23, Troop Ship,      (9,350 tons), 32-19N x 134-58E