Wahoo Final Battle Report

Following is the translation from the original Japanese battle report that resulted in the sinking of the Wahoo. It was translated in August of 1995 after locating it in the Japanese Naval Archives. The form of Japanese used was technical and took considerable effort on the part of the translators. Much of the Japanese text was using arcane war-time language. Links to the figures in the report are included. The English notes along side the Japanese were made by the translators.

Also consider the analysis made based on the Japanese battle report and the circumstantial evidence.

Wahoo Final Battle Presentation
The Sequence of Events based on the latest information


Wahoo Final Battle Photos and Documents

During the summer of the year 2000, researcher Keiko Takada worked with personnel at the Japan National Institute for Defense Studies to uncover the documents detailing the final hours of the Wahoo. Some, such as the photos, where misfiled under the wrong date which may explain why they've not come to light before. The MacKinnon Organization has obtained permission to publish these on this web site.  Further duplication is not permitted without permission from the Japan National Institute for Defense Studies.
 

Battle area map
Wahoo under attack photo #1
Wahoo under attack photo #2
Soya Strait Deployments 1943

Prelude (notes by Bryan MacKinnon and Keiko Takada)
The Wahoo was first sighted by a shore battery which fired upon it.  The Wahoo immediately submerged to complete the crossing. It then possibly struck a mine which forced it to turn back to the west for possible internment in Russia. While heading west, the Wahoo was first sighted by Wakkanai based aircraft.

Attack Report No. 17 (Attack; Oct. /11)
OOminato Air Fleet of the Japanese Navy
Date 1943/Oct/11
 

Contents

  1. Plan
  2. Progress or Expiration
  3. Command & Report
  4. Achievement & Damage
  5. Military Force Condition or Situation
  6. Distinguished Services
  7. Reverence or Epilogue

 Plan

  1. Duty

    2. Since July of 1943, we have established Otaru Base and Wakkanai (Oonuma) Base and sent 3 scout plans to each base (six total) for connecting with ships and to patrol around cape Sooya (on the east coast of Karafuto at which is east of Cape Shiretoko, Sooya Straits, and east coast of Hokkaido).  To escort ship fleets and another Base is also on duty.
  2. Preparations of Operation

    3. None

Progress or Expiration

 
Time & Weather Content
Fine 10% Cloud 2000 meters; Sight 30 meters available; Wind 6 meters West
07:55 For a few days, we have had information about submarine activity and begin patrol duty; Take Off
09:20 12 Nautical miles away from Cape Sooya, we found an oil slick (10 x 5 meters). Investigation determined what appeared to be a conning tower. After we recognized this, we used first bomb (no. 6) and turned around to confirm hitting. We could find the submarine body and wake of a propeller;  we used a second bomb and found a gushing of oil and bubbles (fig 1).
09:40 Return to base
09:50 Arrival at Base
1st attack; A/C No 32. WAKKANAI BASE
10:00 Take off
10:10 On stage
Scattering the oil, the submarine went 2 knots and 315 degrees ahead under water.  We used 2 bombs at a stretch (total 4), submarine was spouting oil and bubbles (diameter 30 meters) (fig 2)
10:35 Return to base
10:45 Return to base
2nd attack; A/C No 319. WAKKANAI BASE
10:15 Take off
10:25 On Stage
Scattering the oil, submarine went west.  After using 4 bombs, we found a streak of bubbles. The Submarine went west and we could not find the body (fig 3)
11:05 Return to base
11:15 Arrival at base
3rd attack; A/C no 320 WAKKANAI BASE
10:20 Take off
10:34 On Stage
We found the oil (2000 x 30 meters).  Spread is almost zero.  We used 2 bombs but no change in the oil situation (fig 4).
4th attack; A/C no 32. WAKKANAI BASE
11:20 Take off
11:30 On Stage
From 60 to 70 meters ahead of the oil, we found bubbles so we used 4 bombs and oil and bubbles were spouting in large quantities. (fig 5).
11:50 Return to Base
12:00 Arrival at Base
5th Attack; A/C no 320, WAKKANAI BASE
11:20 Take off
11:30 On stage
We found the oil (1500 x 40 meters) which was still spouting the oil
11:34 1st bomb was used
11:38 Second bomb was used with no change in the oil situation (fig 6)
11:45 Return to base
11:55 Arrival at base
6th attack; A/C no 319, WAKKANAI BASE
11:35 Take off
11:45 On stage
The oil situation has not changed.  After using 4 bombs, two streak bubbles (with oil).  Spouting of the oil and bubbles was heavy (fig 7)
12:05 Guided a ship
12:50 Return to base
13:00 Arrival at base
7th attack; A/C No 320, WAKKANAI BASE
12:10 Take off
12:20 On stage
12:30 We found bubbles 100 meters ahead of the oil.  Two bombs were used. The oil gushed out much more and the submarine went ahead 330 degrees very slowly (fig 8)
12:45 Guided two ships
13:05 Return to base
13:15 Arrival at base
8th attack; A/C No 312. OTARU BASE
11:20 Take off (Otaru Base)
12:28 On Stage
We found oil (1500 by 30 meters) which was still gushing.  Ahead of the oil, we found the wake of the submarine.
12:38 We used 2 bombs but with no apparent effect (fig 9)
12:47 We used marker and guided a ship
12:50 The wake of the Submarine had disappeared
12:53 Return to Base
13:05 Arrival at Wakkanai base
9th Attack; A/C No. 36, Otaru Base
11:45 Take Off (Otaru Base)
12:50 On Stage
13:00 We used 2 bombs but did not see any effect (fig 10)
13:10 Return to BASE
13:20 Arrival at WAKKANAI BASE
10th attack; A/C No 32, Wakkanai BASE
13:10 Take off
13:20 On Stage
13:30 We used 4 bombs but did not see any effect. The submarine had stopped and was gushing oil and bubbles (fig 11).
14:30 We did reconnaissance
15:10 Return to BASE
15:20 Arrival at BASE
11th Attack; A/C No 312, OTARU BASE
14:05 Take Off (Wakkanai base)
14:20 On Stage
14:23 We used 2 bombs but did not se any effect (fig 12)
14:35 Return to Base
14:45 Arrival at OTARU Base
12th Attack; A/C No 36, OTARU BASE
14:40 Take off (WAKKANAI BASE)
14:50 On Stage
15:40 Kept watch this time and returned to base
16:55 Arrival at OTARU BASE
13th Attack; A/C No. 319, WAKKANAI Base
15:20 Take Off
15:30 On stage
15:35 We used two bombs but did not see any effect.  Guided ships (fig 13)
16:30 Floating oil has stopped and crude petroleum had spurt out in large quantities.
16:45 Return to BASE
16:55 Arrival at BASE
14th Attack; A/.C No 320, Wakkanai BASE
 16:15 Take Off
16:25 On Stage
16:30 We used 2 bombs and found the oil and bubbles increasing much more (fig 14)
17:05 Return to BASE
17:15 Arrival at BASE
Attack had completed

Command and Report

 
DISPATCH RECEPTION CONTENTS ASSORTMENT
11 09:48 A/C 19 11 09:50 WAKKANAI BASE FINDING SUBMARINE (BODY) OFF CAPE SOOYA 42 DEG 12 NM LAMP (WIRELESS BREAKDOWN)
11  09:55 WAKKANAI BASE 11 10:25 OTARU BASE A/C 19 HAS FOUND SUBMARINE OFF CAPE SOOYA 42 DEG 12 NM. AFTER ATTACKING, THE SUB SPURTED OUT OIL AND AHEAD WEST DIRECTION.  SO WE TRY TO ONE BY ONE. WIRELESS
11 10:50 A/C 19 11 10:58 WAKKANAI BASE SPOUT BUBBLE WIRELESS
11 10:55 OTARU BASE 11 10:59 A/C (WAKKANAI) ATTACK A SUBMARINE OFF CAPE SOOYA WIRELESS
11 11:40 WAKKANAI BASE 11 12:00 OTARU BASE SINCE 10:50, BOMBS HAVE HAD EFFECT CAUSING SPOUTING OF BUBBLES AND OIL. SPEED IS SLOW AND STILL GOES WEST. 22 BOMBS USED. WIRELESS
11 11:40 OTARU BASE 11 12:05 WAKKANAI TO A/C TAKE OFF WIRELESS
11 12:55 A/C 12 11 12:58 OTARU BASE ON STATION 
OTHER TWO A/C AND TWO SHIPS ARE ATTACKING. 1500 METER LENGTH OIL SLICK. FOUND SUB'S WAKE		 WIRELESS
11 12:15 WAKKANAI BASE 11 15:09 OTARU BASE AT 14:00 SPEED OF SINKING SUB IS ALMOST ZERO. OIL SLICK IS 2500 X 40 METERS. 5 SHIPS STOP ATTACK. 24 BOMBS USED
11 17:00 OTARU BASE 11 17:04 WAKKANAI BASE AT 17:00 TWO A/C RETURN TO BASE
11 17:45 11 17:04 AT 17:15 ALL A/C BACK TO BASE.  200 METERS FROM END OF THE OIL ARE TWO STREAKS. 1000 X 50 METER OIL SLICK. FOUR SHIPS WERE ATTACKING SO THIS WAS HALTED. 40 BOMBS WERE USED

 ACHIEVEMENT & DAMAGE

  1. Achievement: SINKING ONE SUBMARINE.

    2. Next morning early, 12th patrol air craft went to the engagement stage for confirmation. Heavy oil slick was reported to the NE and thinner layer of the continued for 5000 meters.
    Report from commander of Sooya Base to admiral of OOMINATO BASE by teletype.  From the reports of the aircraft and ships, nothing floating or moving near the battle position.  The oil had been spouting still at 16:29 so we made sure the attack was successful as expected by the air craft report (REPORT No.; SECRET 12614).
    Watch resumed.

MILITARY FORCE CONDITION OR SITUATION

After the battle, the number of air craft for attacking available are:
    WAKKANAI BASE 3 (3 prior to attack)
    OTARU BASE 3 (3 prior to attack)

DISTINGUISHED SERVICES

  1. Since October 2 around the coast of Nihonkai sea, there were 2 night attacks with a submarine located one time. We had [detected] a submarine crossing Cape Sooya and on October 11, careful patrol was executed. A/C no. 1, patrolling from Wakkanai base, found an oil slick 10 meters in length which was the initial contact with the submarine. Immediately, the attack was commenced and it continued with cooperation between Wakkanai and Otaru bases.  For three hours before the ships reached the battle, we had attacked the submarine and it was sunk as evidenced by the spouting oil and bubbles. Attack efficiency was very great.
  2. ORGANIZATION

REFERENCE OR EPILOGUE

  1. Lesson: none
  2. Figure: See appendix 1 and 2

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