[paulhager]

U.S.S PICUDA (SS 382)
c/o Fleet Post Office
San Francisco, California

CONFIDENTIAL August 6, 1944

From: The Commanding Officer
To: Commander-in-Chief, United States Fleet

Subject: U.S.S. PICUDA (SS 382), Report of War Patrol #4.

Enclosures: pictures and charts, covering fourth war patrol.

Bernard H. Schwartz

(A) Prologue

A few old comrades move on to new assignments. A new Chief named Fred Austerlitz joins the crew. He comes highly recommended as a torpedo expert. Austerlitz is assigned the billet in the aft torpedo room left by PO 1st Putnam.

Torpedo loadout: 8 Mark 18 – stern; 8 Mark 14, 8 Mark 18 – bow.

(Unless otherwise indicated, all times below are GMT.)

(B) Narrative

13 JUN – 17 JUN
Left Majuro – made high speed run to Manus Island to top off tanks and proceed to PZ.

Along the way received several reports which suggested major IJN Fleet operations were in progress:
0200 14 JUN, USS Redfin reported 4BB, 4CV, 8CA, many DDs; 5° 00’ N, 119° 38’ E, 10°T, 12KTS.
2030 15 JUN, USS Cavalla reported 15+ large combatants; 11° 50’ N, 131° 52’ E, 50°T, 12KTS.
2200 15 JUN, USS Seahorse reported BBs, CAs, DDs; 5° 25’ N, 128° 15’ E, 20°T, 15KTS.
0740 16 JUN, USS Flying Fish reported heavy units; 12° 45’ N, 124° 20’ E, 90°T, 12KTS.
1530 17 JUN, USS Cavalla reported an AO and 3DD; 11° 43’ N, 130° 25’ E, 10°T, 12KTS.

Connecting the dots suggested a battle might be in the offing to the NW. We were nowhere close.

18 JUN – 27 JUN
In transit to PZ. Arrive 2300, 27 June.

On 21 June, received reports of a carrier battle in the vicinity of the Marianas. Sounded like we gave the IJN a real pasting!

28 JUN
Attack #1
A single crossed our path: a Momoyama Maru. Hit the Maru with a perfect shot from the stern right under the stack. Broke her back.

We have nothing but praise for the designers of the Mark 18. It’s accurate and reliable – we’ve never had a dud. In contrast, we’ve had some duds with the Mark 14.

29 JUN
Attack #2
Just before sundown, another single sailed into range. We were able to get into position for a stern tube shot with our target silhouetted by the fading light of the Western sky.

The ship, a Kinposan Maru, went dead in the water but failed to sink so we moved to 2200 yards off the stern, which had no gun mount, and reduced the ship to a burning and sinking hulk with the 5”.

30 JUN
Attack #3
Moments after receiving orders to patrol in the East China Sea, another ship hove into view. Amazingly, it was the third unescorted merchant ship we’d encountered in as many days. We attacked from 2800 yards off the track. A Mark 14 set for 2’ under the keel was used – it detonated just behind the stack.

That should have finished the Heito Maru but it stubbornly remained afloat. We surfaced and began shelling it. The first several rounds were either wide of the target or overshot. The ship began firing toward us just as a 5” shell finally struck the ship in the vicinity of the stern cargo hold. There was a brilliant flash followed by a rising fireball.

Three torpedoes and a few 5” rounds had sunk 3 enemy ships – we were off to a very good start.

We secured from general quarters and set course for our new PZ.

31 JUN
Attack #4
Just before arriving at our patrol zone, a flotilla of sampans crossed our path. The gunners could always use some practice so we fired on them with both the 5” and the 40mm, sinking 2. Then we continued on.

An hour or so later radar picked up an approaching plane. We dived for an hour and then resumed our course.

01 JUL – 04 JUL
Patrolling.

Attack #5
We had been ordered to patrol in this area for 96 hours and we were close to time to report in to ComSubPac when an unescorted merchant approached from the East – speed was 10 knots, course was 273°T. Made a surface attack from 1600 yards using a Mark 14. Result: 1 shot, 1 kill.

Shortly after our victory, ComSubPac sent a flash message alerting of a convoy en route to the Home Islands traveling through the Formosa Strait. We were close to the track of this convoy and therefore plotted an intercept course. At the same time we reported in to ComSubPac which approved our stalk of the convoy, after which we were to patrol 100 nm West of Manila.

05 JUL
At 0525 radar picked up ships at 34000 yards bearing 135. This couldn’t be the same convoy, which had to still be some distance to the SW. We counted 15 ships in the convoy: position 26° 18’ N, 121° 40’ E; Course 90°T, Speed 10 knots. Twelve ships were in 3 columns, 3 abreast. There was an escort running patterns ahead of the center column, either an escort or a small freighter trailing the center column, and about 3000 yards back from it, an escort running patterns.

We initiated an end around maneuver at 16 knots and for the next hour closed the distance to 20000 yards while pulling ahead. At 0635, position was 26° 18’ N, 121° 51’ E; Course 90°T, Speed 10 knots.

A check of the ephemeris revealed that, if the convoy continued at its present course and speed, the Sun would set at 1046 – moonrise would be at 0955. The moon would be just short of full. We could attack in 4 hours and 25 minutes – 12 minutes before the end of civil twilight and 1 hour 5 minutes after moonrise. Too bright for a surface attack at anything closer that 3000 yards. With clear weather the moon would only get brighter as it rose in the sky, again precluding a close-in surface attack.

The alternative was to make a submerged daylight attack ASAP but that made it more likely the escorts would tie us up long enough for the convoy to escape. Fortunately, it would take at least another hour to get into position for the daylight attack – time we could use to consider our options.

Attack #6
The decision was taken out of our hands: the convoy changed course at 0810. New Course: 10°T; New Speed 8 KTS. Now we had to run a new end around.

We were in position a little before sunset. The lead ship in the center column was chosen as a reference target. We submerged when the lead escort was at 9000 yards – even in the fading twilight, the moon made it far too bright to remain on the surface.




The center column leader proved to be a Nagara Maru – perfect! There was another Nagara in the far column, number 2 position. All of the other ships were smaller. The center Nagara would remain the target – we’d just refine the solution. The only lingering issue was how many torpedoes to allocate. We settled on the 3 Mark 14’s in tubes 1-3 – a miss would have a decent chance of hitting a ship in the adjoining column. Torpedoes 1 and 3 were set for 15 feet and 12 feet respectively. Number 2 was set for 26 feet, magnetic trigger.

We fired the spread and dove the boat. Depth here was only 430’ which was barely enough room to maneuver.

The first torpedo struck right on schedule at 11:19:41.




Numbers 2 and 3 also hit. She was done for.

We found a thermal at 270, leveled off at 300, and went to silent running. We were unmolested by the escorts.

At 1155, we secured from silent running and began reloading torpedoes. Rose to radar depth at 1300. An escort was conducting a sprint-drift search, range 9000, bearing 200. We surfaced and set course for our new PZ.

06 JUL
In transit to PZ.

Attack #7
A singleton showed up on the radar screen at 1930: Course 358°T, Speed 11 KTS. It turned out to be a Nagara Maru. Got into position for a stern shot and fired a spread of 2, both of which hit.

Two hits should have sufficed but the Maru stubbornly sailed on. We surfaced and used the deck gun to convince her she was dead.

07 JUL
Attack #8
Yet another unescorted merchant strayed into our path. Initially it was traveling at 11 knots, 30°T, however, it changed course on us, necessitating some rapid adjustments on our part. The target, an Akita Maru, slowed to 9 knots, then sped up to 10 just before we hit it with a Mark 18 from tube 4. Her back was broken and we left her to her fate.


08 JUL
Reached PZ.

09 JUL – 10 JUL
Patrolling. Harassed by enemy aircraft from dawn ‘til dusk.


Attack #9
Patrolled within radar range of the entrance to Manila Bay. Late on the 10th, target appeared heading North: 11 KTS, 344°T. We were already in a good position to attack so we tracked its approach over the next hour-and-a-half.

11 JUL
The actual attack took place took place at 0012 on the 11th. A single Mark 18 was fired under the keel of the target, a Hakusika Maru. Wind was brisk and waves were a bit choppy, which makes such shots problematic, as was the case this time. The torpedo detonated but didn’t seem to significantly damage to the Maru, which commenced a series of S-turns. We turned the boat to pursue and readied the Mark 14’s in tubes 1 and 2, setting them for 15 feet and high speed. Had to guestimate the target speed and course. Fired both with a 1 degree spread. The first was dead on target, the second missed astern – our first miss of the entire patrol!




Viewed through the periscope it was not immediately apparent that the second hit had much of an effect. However, after a few minutes, the ship slowed and began to settle by the stern. The end came abruptly seven minutes later as the Maru slid, stern first, into the Pacific.


Attack #10
This PZ had been very good to us and our good fortune was to continue. Several hours later, a blip showed up on radar – a ship headed West: Speed 10 KTS, 273°T. We’d have to chase it but with all diesel generators pouring amps into the motors, we quickly overtook it. Then it altered course, coming to 257°T and it slowed to 9 KTS.

The attack was made from 1600 yards – a single Mark 18 from tube 2. It struck just behind the stack and split the ship – a Ryuun Maru – in two.

We had 10 torpedoes remaining and had sunk just over 49000 tons of enemy shipping.


12 JUL – 13 JUL
Our time in this PZ expired so we reported our status to ComSubPac. Our new PZ was closer to home: East of Okinawa.

We proceeded to our PZ at two-engine speed.

14 JUL
Attack #11
Early on the 14th, a ship crossed our path: Speed 9 KTS, Course 239°T. Setup for the attack was easy. Then the target threw us a curve and changed course and speed: 11 KTS, 261°T. Some fast footwork and we again had a good attack position, 1600 yards off the target’s track. Radar and sonar gave us a good solution on an Akita Maru. Then something strange happened.

As we were preparing to fire our last Mark 14, the Maru slowed, its searchlight pierced the night, and it commenced making S-turns. Since we had been submerged for the last several thousand yards of the target’s approach because of light conditions and our own phosphorescent wake, it was inconceivable that the target saw our periscope. The alternative was equally unlikely – that it had listening gear and was reacting to our final ranging sonar pulses.

Irrespective of the reason our target was taking evasive action, the attack continued. We had to rapidly recompute course and speed, which amounted to some educated guesses plus Kentucky windage. The Mark 14 lanced toward the target at 46 knots. From the periscope it was possible to see the ship’s searchlight fix on the torpedo’s wake and the ship begin to accelerate and turn away. It was too little, too late.






The ship completed its turn, stopped and settled by the stern.

We surfaced and continued on toward our PZ. So far we had sunk over 50000 tons of enemy shipping and had 9 torpedoes – all Mark 18’s – remaining.

15 JUL – 17 JUL
Detected approaching enemy aircraft. However, just before we dived the boat, our radar detector sounded – the aircraft had radar! Fortunately, we’ve got inverse squared versus inverse to the fourth power in our favor – that and good old American know-how. We surfaced after an hour.

There were no further incidents on the way to the PZ, which we reach early on the 17th.

18 JUL – 20 JUL
Patrolling.

21 JUL
Attack #12
Surface contact – 0105, Speed 11 KTS, Course 253°T. Tracked for the better part of an hour, then the target changed course/speed at 0155: 9 KTS, 228°T. It appears that, often as not, the enemy zigs around the top of the hour.

This time we didn’t use active sonar to refresh our solution – we strictly relied on popping up the scope.

The target was allocated 1 Mark 18, set for a foot-and-a-half below the keel. The hit was right under the stack, which should have broken the target – a Ryuun Maru – in half.




If there is a slight variation in a torpedo’s depth keeping, which might be expected in heavy seas, then that could explain the observed behavior: sometimes the torpedo strikes the hull; sometimes the torpedo goes a few feet too deep which attenuates the explosive bubble effect. Seas were moderate, not heavy, for this attack. Perhaps even that was enough to disrupt the depth keeping.

The Maru was sailing away, with a distinct starboard list. When it was stern on, we surfaced – the ship only had a bow deck gun and we should be in the shadow provided by the superstructure. We opened fire at just under 2000 yards – the first two shots were wide but then our gunner had the range and rocked the target with several hits. The ship began to turn, bringing the bow gun to bear. The first shot was very short. The second coincided with one of our hits and was much closer.




We directed the gunners to target the enemy’s main armament. They scored a hit – or so we thought until the Maru responded with a shot that showered the bridge watch with spray. We crash dived.




We leveled off at 100 and allowed the ship to open the distance, then returned to periscope depth. Once again the ship was presenting its stern so we surfaced again – this time the range was 2400. Several unanswered hits sufficed to finish her off.




When our operations in this patrol zone ended, ComSubPac ordered us back to the Philippines – this time to patrol in a 100 nm radius centered 40 nm North of Calyan Island. Fuel was hovering just above 50% so we couldn’t do too many more of these long distance jaunts.

22 JUL – 24 JUL
In transit to PZ.

Received message from ComSubPac on 22 July: new base at Saipan. Somewhat ironic given the devastation we’d visited upon the Japanese there during our last visit.

Reached PZ.

24 JUL – 27 JUL
Patrolling.

New patrol zone 150 nm West – the overlap happened to find us starting our patrol in the PZ.

28 JUL
Attack #13
Our last attack of this, our fourth patrol, began at 1201. While running the Eastern leg of our search pattern we found a small convoy of 7 ships heading north: Position 20° 33’ N, 119° 50’ E; Speed 11 KTS; Course 01°T. The convoy was assumed to consist of 3 merchants in a single column in the center and four escorts in a diamond centered on the last ship in the column. When we’ve encountered this formation in the past, the ships in positions 2 and 3 are high value – often Nagara Marus. We considered the possibility that this time they might be large tankers.

We had to do an end around – there was nothing for it but to go to flank speed, burning up more of our precious fuel. Mindful that formations often zig at the top of the hour, we chose an oblique course that should give us a good setup ASAP. Although the moon was up and fairly bright, seas were rough and there was a light mist. A surface attack was a possibility.

We got a rude awakening when we closed to within 20000 yards of the lead merchant – roughly 18000 yards from the near escort: the radar warning sounded. Although we had the advantage of better radar equipment and, of course, the radar equation, this development played hob with our plans. Clearly, a surface attack was now out of the question. A submerged attack made it more likely that the escort’s passive sonar would pick us up before we could get close – though this situation should be mitigated somewhat by the wave action’s effect on the hull-mounted sensors.

The quick attack was no longer feasible – we changed course to a parallel track at 20000 and began to pull away. The constant radar warning became annoying so we turned it off – it wasn’t telling us anything we didn’t already know.

Top of the hour came and went and the convoy doggedly continued at the same course and speed.

We finally reached a position about 6000 yards off the convoy track and turned 90 degrees to it. We submerged to decks awash and continued on at 5 knots, taking our final radar readings on the lead merchant. Once we had a good solution we dived the boat – distance was around 3000 yards from the track. The hope was to find a reasonably shallow thermal that we could exploit to get close, then come to periscope depth inside the screen.

We found the thermal at 220. We continued down to 250, silent running. We were roughly 2200 yards off the track.

When the lead escort passed our bow, we began to rise to periscope depth. If we’d timed things right we should have a good shot on the number 2 merchant, then we could submerge to the safety of the Pacific’s depths.

The timing was near perfect. When the periscope broke the surface it was pointed on the bearing (135) of the flank escort, which was oblivious to our presence. Swiveling quickly showed the lead merchant, an Akita Maru was just crossing our bow. In the number 2 position was a Nagara Maru. A quick check of number 3 brought a very welcome surprise: a Taiyo CVE! That would be our target. No time for fanciness – the 4 remaining Mark 18’s in the bow had been set for 12 feet, impact pistol. We got the solution and fired all 4 at the CVE. Then we dove for that thermal at 4 knots.

The first torpedo was a couple of seconds late on target. A couple of seconds later, number 2 hit.




Numbers 3 and 4 followed quickly. The men involuntarily cheered. Who could blame them? However, celebrations ended as we crossed the thermal and resumed silent running.

We leveled off at 420 and made a slow turn to course 180. Escorts dashed about upstairs but never dropped any depth charges nor gave any indication that they had the faintest idea where we were.

An hour after the attack most of the convoy had moved on but one escort was laying back, making sprint drift searches 2000-3000 yards away, bearing 115. We felt safe enough to secure from silent running and go to 3 knots.

After another couple of hours, the escort was no longer in evidence. We went to periscope depth and did a couple of 360 scans. Nothing. Then we went to radar depth and did two complete sweeps. Nothing. Surfaced the boat at 1752 – almost 3 hours to the minute after firing at the target. We were alone.

Reported to base and resumed patrol.

30 JUL
The time in the PZ had expired so we contacted ComSubPac and got the expected, “return to base” message.

31 JUL – 4 AUG
Returning to new base at Saipan. Arrived 4 August.

(C) Fuel Consumed
84%

(D) Weather
Normal for the area(s).

(E) Torpedoes Expended
20 (8 Mark 14, 12 Mark 18) – 10 merchant ships, 1 CVE + 2 Sampans sunk by gunfire; estimated tonnage, 77,743.

(F) References
See Patrol 3
See Patrol 5