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Standard histories of the World War II campaign against Japan have almost nothing to say about them. They were judged too small and insignificant to be counted in the official record of Japanese ships sunk by our forces during the war, so the usual tallies of ships credited to each of our submarines do not include them. Descriptions of the Imperial Japanese Navy provide little information about them, and there was nothing like them in the U.S. Navy. Our sailors and airmen knew them as picket boats, and our submariners found them to be real “thorns in the flesh.

The Navy’s first encounter with the Japanese picket boats occurred on 24 February 1942 in the course of an air raid on Japanese installations on Wake Island, during which two pickets were sunk. A more significant contact transpired on 18 April 1942 when the NITTO MARU #23° spotted and reported the task force carrying Lt. Col. James H. Doolittle’s bombers toward Japan, thereby breaching its security and forcing the planes to be launched earlier than intended. The NITTO MARU #23, a 90-ton steam trawler, and two additional pickets were sunk and eight others damaged by planes from the carrier ENTERPRISE and gunfire from the cruiser NASHVILLE, but they had fulfilled their mission and significantly reduced the effectiveness of the Doolittle raid.

What manner of opponents were these boats? Unlike the U.S. Navy, which preferred to build most of its smaller types of warships from the keel up, the Japanese Navy mobilized hundreds of fishing craft and other commercial types to serve as converted gunboats, minesweepers, patrol boats, submarine chasers, and auxiliaries of various kinds. Alterations were held to a minimum, the ships retained their commercial maru names, and many of the crews were simply enrolled as reservists and retained on board.

Among these conversions were 404 former ocean fishing vessels designated tokusetsu kanslzitei or specially equipped guard boats. They are listed as ranging from 32 to 269 gross registered tons, which measures only their commercial cargo capacity; as warships their displacements probably fell mainly between 150 and 250 tons. The official register describes them variously as steam vessels, ketches, or schooners, hut all had engines in addition to any sails carried. They were armed with one or two light guns, such as older model 5-or 6-centimeter short-barreled weapons, plus machine guns, rifles, pistols, and two to four depth charges. Most importantly, they were fitted with powerful radio transmitters and antennas mounted on high masts for long-range communications. With reservist crews augmented by regular naval commanding officers, gunners, and radio operators, their main function was to patrol picket lines 500 to 700 miles off the Japanese coastline and warn of approaching enemy forces.

Organizationally, the pickets in the northern Pacific came under a unit called the 22″d Squadron, which also included several attached converted gunboats and miscellaneous support craft, with headquarters in Yokohama. Those in the south came under the 4th Fleet. Within the northern group, 194 boats were assigned to the 1st through 6th Guard Forces or Fleets, which were responsible for the main picket line sectors. In the south, 74 were assigned directly to the 4th Fleet. The rest were divided among 20 or more organizations including other main fleets, local defense fleets, and base or district forces. Casualties were high: at least 179 were sunk by U.S. forces-28 or more by submarines-and about 21 were lost by non-combat causes. Most of the rest are known or presumed to have been returned to their owners after the war.

To make matters more confusing, there was an additional set of pickets called =atsuekisen kanshisen or miscellaneous guard boats about which less is known. These were under naval control but were manned by civilian crews and presumably were not as well armed as the regular converted boats. The publication Warships o(the Imperial Japanese Navy. 1869-1945 by Hangeorg Jentschura, Dieter Jung, and Peter Mickel omits many of the 404 previously described but identifies as guard boats 124 that are not included in that group. It also reports that 32 of these so-called pickets were sunk by submarines. According to more authoritative sources, most of these vessels were actually serving in other roles, or are listed incorrectly. As will be seen, submarine skippers were never sure what kind of armed Japanese small craft they were engaging.

Our submarines began to encounter some of these little ships as the earliest patrols from Pearl Harbor approached Empire waters, but the skippers had little guidance as to dealing with them. Up until World War II, the leaders of the Submarine Force were divided into two camps regarding the proper use of the deck gun. The faction headed by the influential Admiral Thomas C. Hart believed that gun battles should be avoided as jeopardizing the submarine’s primary mission of scouting in advance of the battle fleet and torpedoing enemy warships. Hart, who was president of the General Board when the characteristics of the WWII fleet submarine were developed, would accept nothing larger than a 3″/50 caliber dual-purpose surface and anti-aircraft gun as a last-ditch defense weapon. Additionally, peacetime training emphasized evading anti-submarine vessels and attacking enemy ships with minimum exposure of the periscope by going deep and firing torpedoes on sonar bearings.

The leader of the younger, more offensive-minded, party was Charles A. Lockwood, who favored the powerful 5″/51 caliber gun. As a compromise, Hart agreed to allow the installation of strong gun foundations starting with the Tambor class in case it should later be decided that a heavier gun was necessary. The reaction of submariners to the picket boats is thus closely related to the development of surface gun tactics and the general policy regarding attacks on minor targets.


The first recorded submarine attack on a small Japanese vessel was made on 20 February 1942 during the second patrol of TROUT (SS 202) under the command of Frank W. Mike Fenno, Jr. Returning from a supply run to Corregidor with 20 tons of gold and silver as ballast, he made a night surface attack on what he identified as some sort of patrol vessel, fired three torpedoes and claimed one hit. He was credited with a 200-ton PC, but this is not supported by Japanese records. In endorsing the patrol report, the squadron commander noted that the proper course in such cases was to avoid action, but approved Fenno’s decision in this particular instance. ComSubPac concurred.

Next, three noteworthy encounters occurred during the second patrol of POLLACK {SS 180). On 10 March 1942 skipper Stanley P. Moseley submerged and made a periscope inspection of two sampans, which he found were fishing and showed no sign of guns or radio antennas. The next day he came upon them again, and decided to attack them at night with his deck guns. The first one received three hits from the 3″ gun and was set afire. The second sampan, swept by 200 rounds from the .50 caliber machine gun, appeared to settle. Neither case was written up in the attack section of the patrol report and no damage was claimed, consequently they do not appear in the Submarine Operations Research Group (SORG) analysis of submarine attacks. Similar attacks in a few other early patrol reports were ignored in the same way, as if too trivial to warrant mentioning.

Earlier that day Moseley had made a successful torpedo attack on the 1,454-ton cargo ship FUKUSHU MARU, sinking it with one hit out of four fired. Later, six torpedoes fired at another freighter failed to hit, whereupon Moseley battle surfaced and engaged the target with his deck gun. The 3″ gun jammed after the first shot, but 11 more rounds were fired by hand, resulting in two hits. However, these failed to slow the target, which Japanese records identify as the slightly damaged BAIKAL MARU, 5,266 tons. On 26 March lookouts sighted a converted fishing boat, painted white, with a large radio antenna, and sporting four machine guns. In retrospect this appears to have been a picket boat, but Moseley decided it was a Q-ship (or decoy) and proceeded to avoid. Many other skippers would soon report similar or worse gun failures, while some were suspicious of Q-ships throughout the war.

The endorsements to this patrol report are revealing. The division commander noted that this was the first time 3″ and .50 caliber guns had been used by a Pacific Fleet submarine, but criticized that it was a needless waste of torpedoes to fire them at a 150-foot ship: either use the gun or let it go. As for the sampans, they were “only fishing boats and are no excuse for a submarine to dive.” ComSubPac approved the division commander’s comments and also noted: “This is the first instance where a submarine of this Force has been permitted by weather or other circumstance to use the gun against the enemy.” He added that using the gun gave the commanding officer freedom of movement and at the same time “started the destruction of Japan’s vital fishing fleet.

On POLLACK’s next patrol Moseley made more gun attacks on small craft. On 12 May 1942 lookouts sighted a fishing boat circling on station. It was painted white, had a Japanese flag painted on its clipper bow, tall masts, and a high superstructure from amidships to the stern. Moseley surfaced after dark and left the target burning all over after hits from 66 3″ and 200 .50 caliber rounds; the flames were still visible 65 minutes later. On the night of the 17th Moseley sighted a white light, closed to I 00 yards and raked a sampan with 220 rounds from the machine gun when the firing pin of the 3″ gun could not be cocked. Contact was lost in the darkness and no attack report was submitted. Four more sampans were attacked on 20 May, of which two were claimed sunk, one damaged, and the last left burning. Then on the night of 31 May another trawler was encountered, lying to without lights. Moseley surfaced, blasted the target with nine 3” and 220 .50 caliber shots, and left it blazing. (This ship was the picket SHUNZEI (or SHUNSEIS) MARU #5 of 92 tons, reported sunk with 11 crewmen killed. The other victims, which have not been identified, were probably unarmed fishing vessels.)

In his endorsement, the division commander noted that Moseley’s gun attacks offered conclusive proof “that submarines have little to fear from Japanese sampans and large fishing boats. Judicious destruction of these vessels is a diversion for the crew and is costly to a nation which depends to a great extent on her fishing industry.”

The first gun attack recorded by SORG was made on 11 April 1942 by Eliot Olson during the second patrol of GRA YUNG (SS 209). In a night surface attack against what he thought was a 200-ton fishing sampan, he fired the .50 caliber machine gun until it jammed, then continued with nine rounds from the 3″ gun, three of which he believed were duds, but left the sampan afire and settling by the stern with apparently only two men still alive. Later, however, he observed that the fire had been put out and the craft was under way again. In the patrol report he blamed defective 3″ shells for his failure to sink the sampan, but the division commander praised his aggressive action as highly gratifying. ComSubPac credited Olson with damaging a 200-ton sampan but blamed the crew for the ammunition problem. The fuzes, he said, had to be set on safe when used against surface targets. Olson was apparently unaware that the shells were mainly intended to be used against aircraft. (They were not VT or proximity fuzes; these were not introduced until 1944.


As such comments began to be circulated through the Submarine Force, skippers’ attitudes toward the use of their weapons were bound to change. By war’s end they had sunk hundreds of trawlers, sampans, junks, and small craft of various other descriptions by gunfire. They had also found it prudent to use torpedoes against well-armed small warship types, including picket boats. The Japanese document Guard Forces Ships’ Combat, General Situation lists I 04 encounters of pickets with U.S. submarines, not all of which can be attributed to specific boats. In many cases the submarine avoided action, but in 42 instances the picket boat was sunk or damaged by gunfire. Eleven more were downed by torpedoes, while four others were probably accounted for by submarines that failed to return from patrol. The accounts that follow are not intended to constitute a definitive history of submarine warfare versus picket boats-an impossible task given the limited existing documentation-but will show how the antagonists approached each other as the war progressed.

TRITON (SS 201 ), under the command of Charles C. Kirkpatrick, was on her third patrol when on the night of 23 April 1942 they came across a big trawler estimated at l, l 00 tons. Kirkpatrick fired two torpedoes at the target but missed. He then battle surfaced and attacked it with his deck and machine guns, observing four hits from 19 rounds of 3″ plus damage from 675 rounds of .50 caliber, and a big hole in the trawler’s bow. He noted that this was the first time the sub’s gun crews had fired their weapons against a target in peace or war! (Japanese records show the picket boat SHINKO MARU #5 of 55 tons as shelled and damaged 240 miles north of Marcus Island.) Later, on 15 May 1942, Kirkpatrick made a day gun attack on two sampans, leaving the first wrecked, burning and listing. The crew of the second one abandoned ship, so Kirkpatrick had it boarded, then wrecked by 3″ fire.

ComSubPac commented that the attack on the two deep-sea fishing boats was well conducted, adding that it was interesti11g to note that the ships co11tai11ed neither armament nor radio transmitter. The fishing indust1y is very important to Japa11.” (The victims were the fishing boats KOEN MARU #3 of 38 tons and KAIEI MARU of 110 tons.) No comment was made about the boarding, which also appears to have been the first by a U.S. submarine in the Pacific war.

Kirkpatrick’s exploits were soon matched by Creed C. Burlingame on the maiden patrol of the new SlLVERSIDES (SS 236). While some 600 miles short of the Japanese coast, well north of Marcus Island, on l 0 May 1942 he encountered a patrolling trawler and engaged it with his deck gun and machine guns. Choppy seas made pointing erratic, and several times the crew was knocked away from the 3″ gun. The enemy vessel returned fire with its own machine gun and rifles, and as Burlingame closed to finish it off, it got in one burst at the submarine’s gun crew, instantly killing the second loader, Mike Harbin. Even though the trawler had been hit by at least 12 3″ shells plus machine gun salvos and was on fire, it refused to sink. Assuming that the Japanese could not possibly reach land in that condition, Burlingame resumed course to his assigned patrol area. Shortly thereafter a medium-sized freighter was seen heading for the trawler’s last position. Burlingame suspected, probably correctly, that it was a supply ship for the trawler, so he hung around hoping in vain that it might come back. The next day the crew buried Harbin at sea.

Upon his return, Burlingame was credited with sinking a 350-ton trawler. (In fact, his target was the 131-ton picket boat EBISU MARU #5, which reached port with seven men killed and two badly wounded. It would be encountered again by another submarine less than a year later.) Probably the most noteworthy thing about the higher-ups’ endorsements is that neither ComSub-Div 10 l, ComSubRon 8, nor ComSubPac made any mention of Harbin’s loss.

On 31 August 1942 Burlingame and SILVERSIDES, at sea again on their second patrol, sighted a trawler and quickly opened fire. Closing to 50 yards, they scored three hits with the 3-incher and raked the craft with the machine gun for half an hour. “As certainly no one was left alive on board and the trawler had a heavy list to port, was settling rapidly, and smoking heavily, we left the area,” he reported. (This ship was the 42-ton civilian fishing vessel MIYO MARU, which survived with the loss of only one man.)

The next night they spotted an unlighted ship, closed in, and opened fire on another trawler, which returned fire with a machine gun or possibly a heavier automatic weapon, hitting the submarine’s superstructure several times but causing no damage or casualties. Altogether BURLINGAME made three passes and raked the trawler’s bridge and topside with the .50 caliber machine gun but failed to set it afire. The 3″ deck gun was not used because BURLINGAME considered it of little value at night except at point blank range; also its ammunition was nearly exhausted. (This craft has not been identified, but does not appear to have been a picket.

Another significant attack was made by Willis M. Thomas during the third patrol of POMPANO (SS 189). En route back to Midway at the end of the patrol, on 4 September 1942 they encountered a small craft lying to and identified it as a naval auxiliary. It had the number 163 on its bow and was armed with one 20 mm gun, machine guns, two Y-guns, and depth charge acks. Thomas opened up with his 3”, 20 mm, and .50 cal. guns at 2,700 yards and the third 3″ shell put the enemy’s 20 mm gun out of action. The target was afire and soon sank, causing its depth charges to detonate. One prisoner, a naval rating, was picked up, who indicated that most of the crew had been below eating when the sub attacked. Unfortunately, during the exchange of fire the submarine’s first loader, W. A. Calcaterra MoMMlc, was struck in the shoulder by a .30 caliber bullet. Although taken below and treated by the pharmacist’s mate, he died from hemorrhage, and was buried the next day. In contrast to the treatment of Mike Harbin, he was posthumously awarded the Silver Star and was further honored by having a destroyer escort, DE 390, named after him. (The picket boat was the 83-ton NANSHIN MARU #27, reported as missing and presumed sunk.)

By now it was evident that the little Japanese armed trawlers were serious opponents, and so could be the sea conditions under which they operated. The new SA WFISH (SS 276) under the command of Eugene T. Sands encountered both enemies on 20 March 1943 as she was returning from her first patrol. In spite of very heavy seas, the trawler maintained a speed equal to the submarine’s and kept circling across her bow. SAWFISH opened fire with her 3″ gun and the Japanese responded with what appeared to be a four-pounder. Sands closed, scoring many 20 mm and .50 cal. hits, “twice cleaning out the enemy’s gun crew and twice knocking over a machine gunner who was firing a machine gun from the top of the pilot house.” Three 3″ hits appeared to do little damage and failed to slow the enemy down. Twice the deck gun crew was almost lost as seas piled them against the lifelines. The gun officer, Lt. Clarke, actually went through the lines but held on even as his class ring was stripped off his finger. Then a plane was sighted, undoubtedly responding to a radio call from the picket boat. Sands promptly dived and continued on to Midway. (The picket was SHINSEI MARV of 148 tons, which had been escorting another picket and a gunboat that missed the battle.) The Division Commander merely noted that the gun attack demonstrated Sands’s “well known aggressive character.”

SCORPION (SS 278) on her first patrol, under the command of William N. Wylie, had conflicting experiences in fights with wo small Japanese ships. Early on 30 April 1943 they sighted a patrol vessel of about I 00 tons that was anned with an old-fashioned one-or two-pounder on its pilot house and carried a prominent cage antenna between two masts. Wylie bore in, firing his 3”, 20 mm, and .30 cal. guns. “The action consisted of chasing him around in a circle until he was destroyed. No shots were returned.” The vessel (which has not been identified) was left burned to the water line.

The next morning the sub ran across a bigger patrol craft about 175 feet long, with a steel hull, wooden superstructure, and two masts. It was painted gray with the number 23 on its bow, mounted an old-fashioned 5-or 6-pounder on a high platfonn forward, and carried two racks of depth charges aft. The aggressive picket boat (none other than the EBISU MARU #5, which had accounted for Mike Harbin on SILVERSIDES) charged at the sub, and at 2,000 yards Wylie opened fire with all weapons. At 800 yards the 3″ gun jammed, so he broke off to make repairs and replenish the ammunition supply. The enemy followed for a while, then released a heavy white-smoke float, drew aft and stopped, with the crew drawn up at quarters in white uniforms. As the sub closed to about 400 yards, the pilot house was afire and the forward gun appeared to be out of action, but machine guns and rifles were still being fired from along the bulwarks. At that point Lt. Cdr. Reginald M. Raymond, who was riding as a prospective commanding officer and firing a Browning automatic rifle from the bridge, was hit in the forehead by a bullet that passed completely through his head. The furious skipper swung the sub’s bow directly toward the enemy and fired his last remaining torpedo with a 500-yard run and depth setting of two feet. With a huge blast the picket blew up and disappeared. “When struck, his flag was still at the gaff and he was still firing,” Wylie noted in the patrol report. A rapidly approaching plane then forced the submarine to dive and dropped two depth charges, with the result that Raymond’s body was lost.

On SCORPION’s return, the division commander decreed: “Each boat in this division will dedicate one full tube nest forward” to Lt. Cdr. Raymond. ComSubPac also regretted Raymond’s loss, but added that he was “in full accord with the use f guns in destruction of sampans.” However, he emphasized, skippers must carefully consider the value of the target and the risks involved and the submarine must always maintain the advantage. “Gun battles are always extremely exciting encounters and are definitely morale builders on long and sometimes boring patrols. However, these factors must not jeopardize the ultimate mission of a submarine on war patrol by allowing one’s vessel to be damaged.” As for Raymond, he too had a destroyer escort, DE 341, named in his honor.

For the next several months, skippers seem to have taken a more cautious approach to picket boats. On 6 July 1943 Irvin S. Hartman, in command of venerable S-41 (SS 146) on her seventh patrol, missed the picket SEIYU MARU with two torpedoes. On his next patrol he encountered an old-looking small ship on 14 September that was smoking badly and zig-zagging wildly. It had outriggers on each quarter and peculiar structures on the after deck. Hartman decided it was a decoy and broke off the approach.

Thomas L. Wogan on the eighth patrol of the elderly TARPON (SS 175) on 4 September 1943 encountered a small ship lying to, that fit the now-familiar profile of a picket boat: a 200-foot trawler with abnormally high masts. He opted to make a night periscope attack and fired his last two stem torpedoes. The first one hit and demolished the target, leaving only the stem afloat for another 30 seconds and the sea littered with oil and scattered debris. There were no survivors. (The Japanese records show the 97-ton picket YURIN (or YULIN) MARU as lost at that time.)

Samuel D. Dealey, a notably gung-ho commander, was return-ing from his second patrol in HARDER (SS 257) when two armed trawlers came in sight on 30 September 1943. Dealey immediately closed the range to draw fire from the enemy, and at about 7,000 yards both started shooting. Disregarding the opposition, Dealey closed in further to about 4,000 yards, firing his 3″ gun. At that point one of the pickets got the range and put a salvo directly over the gun crew, prompting Dealey to judiciously back off a bit. After several hits were seen on the larger target, the two enemy vessels drew apart in order to split HARDER’s fire, and finally tried to break away, throwing barrels of burning oil or smoke generators overboard. Closing again, HARDER got more hits until the 3″ ammunition was exhausted. After firing a magazine load of 20 mm shells for good measure, Dealey resumed course for Midway. “The experience gained by the gun crew,” he noted, “is considered invaluable and the boost in morale was very apparent. After having dodged this type of enemy patrol ship for the past three weeks on station, the boys were very glad to ‘dish it out’ for a change.” (Dealey’s opponents were the pickets ASAHI MARU #2 of 164 tons and the 157-ton MATSUMORI (or MATSUSEI) MARU #3, which reported receiving only two shell hits.)

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