The Silent Service Goes to War: Unrestricted Submarine Warfare and the Fleet Boat, 1941–1942

At 17:52 Eastern time on Sunday, 7 December 1941, about four and a half hours after the first Japanese bombs fell on Oahu, the Navy Department in Washington sent a one-line order to the Pacific and Asiatic Fleets: execute against Japan unrestricted air and submarine warfare. At Pearl Harbor it was early afternoon. The battleships were burning, but the submarine base at the edge of the harbor, its piers, its tenders, its machine shops and the great tank farms of fuel oil beside it, had hardly been touched. Four submarines lay in port, undamaged. Within four days the first of them was at sea for Japan. It would take the Silent Service most of two years to make good on that order.

Why it mattered

Japan went to war as an island empire that could not feed its factories from its own soil. Its oil, most of its iron ore and bauxite, much of its rice and the raw rubber and tin of the newly conquered south all had to come home by sea, and the army garrisons it scattered across the Pacific had to be supplied the same way. At the end of 1941 Japan’s merchant fleet amounted to about 6.4 million tons (Parillo). Every ton of shipping that went to the bottom was a ton that could not be replaced quickly, and every cargo lost was oil not refined, steel not rolled or a garrison not reinforced.

The U.S. submarine force was the weapon that went after that shipping, and by 1945 it had done more to strangle Japan than any other. The Joint Army–Navy Assessment Committee (JANAC), working from Japanese records after the war, credited U.S. submarines with 1,113 Japanese merchant ships of 4,779,902 tons, about 55 percent of all Japanese merchant tonnage lost to every cause, and with 201 warships of 540,192 tons. The price was 52 U.S. submarines lost in the war, all but one of them in the Pacific, and some 3,500 submariners, a death rate of about one in five of the men who made war patrols (Blair; JANAC).

None of that was obvious in December 1941. The submarine force had trained for a different war, against warships, under rules that forbade attacking merchant ships without warning. Its torpedoes did not work properly, though no one yet knew how badly. Its Asiatic boats were about to lose their base, and its Pacific boats were about to learn that peacetime caution sank very little. This chapter covers that first year: the decision to fight without restriction, the boats and the men who manned them, and the long, disappointing education of 1942. The torpedo scandal that ran through all of it is the subject of Chapter 2.

Rules written for another war

The United States came out of the First World War as the loudest critic of the German U-boat campaign. Unrestricted submarine warfare against merchant ships had been one of the reasons the country went to war in 1917, and in the 1920s and 1930s American diplomats helped write that grievance into international law. Article 22 of the London Naval Treaty of 22 April 1930, restated in the London Submarine Protocol of 6 November 1936, bound submarines to the same “cruiser rules” as surface warships: a merchant ship could not be sunk until her passengers and crew had been put in a place of safety, and a ship’s boats did not count as a place of safety unless land or another vessel was close at hand. The United States signed both. U.S. Navy regulations and war instructions in force in 1941 still reflected them (Holwitt).

For a submarine, cruiser rules meant surfacing, stopping the target, and waiting while the crew took to the boats, often within range of the merchant ship’s own gun or of a radio call for help. Some officers said openly that the rules made a submarine useless against merchant shipping. A 1935 article by a young lieutenant commander named Hyman Rickover argued that the treaties’ treatment of armed merchant ships made cruiser warfare impossible in practice (Frank, reviewing Holwitt). The submarine force accordingly trained to attack warships, above all the battleships and carriers of the Japanese fleet, as scouts and ambushers for the U.S. battle line.

That training had its own distortions. Peacetime exercises penalized a submarine that showed its periscope or was “sunk” by a destroyer, so commanding officers learned to attack deep, slowly and from long range, firing on sound bearings alone rather than risking a look. Fleet doctrine taught that a submarine on the surface within range of enemy aircraft was a dead submarine. Clay Blair, whose Silent Victory (1975) remains the fullest history of the campaign, judged much of this prewar training unrealistic, and the war proved it so: the cautious habits it bred had to be unlearned at sea, and many of the officers who could not unlearn them were relieved in 1942 and 1943 (Blair; Ransom).

Behind the treaties, the Navy was quietly preparing to throw them out. Joel Holwitt’s study Execute Against Japan (2009) traces the decision through the planning documents of 1940–1941. War Plan Rainbow 3 (December 1940) let the fleet commanders declare “strategical areas” in which merchant shipping could be barred; in February 1941 Stark told Hart he could assume that Japan’s military controlled all merchant shipping in such areas; by September 1941 Stark and his chief war planner, Rear Adm. Richmond Kelly Turner, had decided to authorize unrestricted submarine warfare as soon as war came; in October Cmdr. James Fife carried word to Hart in Manila that the authorization would follow within a week of hostilities; and on 27 November Stark told Hart he would grant it at once. Neither the President nor Congress ever approved the policy explicitly (Holwitt; Frank).

The order of 7 December 1941

The Japanese attack on Pearl Harbor began at 07:55 Hawaii time on 7 December 1941, which was 13:25 in Washington; Hawaii then kept a time zone five and a half hours behind the East Coast. At 17:52 Eastern time Stark’s office sent the order to the commanders in chief of the Pacific and Asiatic Fleets. In Manila, where it was already 8 December, Hart issued his own order to the Asiatic Fleet. Holwitt concluded that Hart acted on his own authority some three hours before Stark’s message; the historian Richard B. Frank, reviewing the evidence, found that Hart’s order followed the arrival of Stark’s. Either way, by the night of 7–8 December every U.S. submarine commander in the Pacific was free to sink any Japanese ship he found, without warning (Holwitt; Frank).

The order

EXECUTE AGAINST JAPAN UNRESTRICTED AIR AND SUBMARINE WARFARE

The submarine base at Pearl Harbor had come through the attack almost untouched. It stood on a small peninsula on the southeast side of the harbor, beside the fuel farm whose tanks held the Pacific Fleet’s oil. On 7 December four submarines were in port, Narwhal and Dolphin at the base piers, Tautog at Pier Two and Cachalot in overhaul at the Navy Yard; none was damaged, and the tender Pelias and the submarine rescue vessel Widgeon at the base piers escaped as well. Japanese aircraft did not attack the tank farm or the base’s shops. Gunners on Tautog and the other boats fired at the attackers with what they had. The failure to destroy the base and the oil was one of the attack’s great omissions, and the submarine force, more than any other branch, would turn it into a weapon: from that base, within days, the boats went to sea.

The Pacific Fleet submarine force was commanded by Rear Adm. Thomas Withers. Of the 51 U.S. submarines in the Pacific, 22 were homeported at Pearl Harbor, a mix of new fleet boats and older ones, several of them away on the West Coast for overhaul (ComSubPac history). The Asiatic Fleet, based at Manila under Adm. Thomas C. Hart, had 29 submarines, the largest single concentration of American submarines in the world: 23 modern fleet boats and six old S-boats of 1920s design (Ransom; some counts give 27). Hart’s small surface fleet could not hope to stop a Japanese invasion of the Philippines; his submarines were expected to.

The fleet boat

The boats that fought the Pacific war were called fleet submarines, or fleet boats, because they had been designed in the 1930s to scout and fight alongside the battle fleet: large enough and fast enough on the surface to keep up with it, with the range to cross the Pacific. The standard wartime designs were the Gato class, of which the first, Drum (SS-228), was commissioned on 1 November 1941 and was the only one in service when the war began, and the nearly identical Balao class, which began to enter service in February 1943. Between them they made up most of the submarine force by 1944: 77 Gatos and 120 Balaos, the last of them completed after the war (Friedman; Alden).

A Gato was 311½ feet long and 27 feet in the beam, and displaced about 1,525 tons on the surface and 2,424 tons submerged. Four diesel engines, built by General Motors, Fairbanks-Morse or Hooven-Owens-Rentschler, drove generators that powered four electric motors geared to two propellers; there was no mechanical link between the diesels and the shafts. On the surface the boat could make about 21 knots and cruise 11,000 nautical miles at 10 knots, enough to patrol off Japan from Pearl Harbor and come home. Submerged, she ran on two batteries of 126 cells each, at a top speed of about 9 knots for an hour or so, or 2 knots for about two days. She carried 24 torpedoes for ten 21-inch tubes, six forward and four aft, and a deck gun, at first a 3-inch/50 and later, in most boats, a 5-inch/25. The Gato’s designed test depth was 300 feet; the Balao, built of higher-strength steel, was rated for 400 (Friedman; Alden).

In practice the fleet boat was a surface ship that could hide underwater. It spent most of a patrol on the surface, running on its diesels and charging its batteries, and went down only to attack, to hide from aircraft or to escape. Its lookouts, two or three of them perched on the periscope shears, were its first line of defense, and radar soon became its second. The SD air-search radar came first; the SJ surface-search radar, which reached the boats in the second half of 1942, gave a submarine the ability to find and track a convoy at night and changed the way the war was fought. By 1944 the typical successful attack was not the submerged periscope attack of the prewar exercises but a night surface attack directed by radar, the method that Richard O’Kane’s Tang would perfect (Chapter 3).

Eighty men in a steel tube

Inside the pressure hull, a fleet boat was divided by watertight bulkheads into eight compartments, from the forward torpedo room through the officers’ country and the forward battery, the control room with the conning tower above it, the after battery with the crew’s berthing, galley and mess, the forward and after engine rooms, the maneuvering room and the after torpedo room. Designed for 60 men, the boats went to war with about 80. Men slept in narrow bunks stacked three high, many of them among the reload torpedoes in the torpedo rooms; junior men often shared, one man taking the bunk as the other went on watch. There was one shower for the crew, rarely used because fresh water came from the evaporators and went first to the batteries and the cooks. The air, once the boat had been down for a day, was thick with diesel oil, cooking, sweat and cigarette smoke.

In return the Navy fed submariners the best food in the service, and the men who served in them were volunteers, screened for health and temperament and paid extra for hazardous duty. A typical war patrol lasted about 60 days, of which perhaps a month was spent in the patrol area; the rest was the long passage out and back. Between patrols the crew went ashore for two weeks of rest, at Pearl Harbor at the Royal Hawaiian Hotel on Waikiki, which the Navy took over for the submarine force, or at hotels in Perth, while a relief crew and the tender or base overhauled the boat. Then came a few days of training and another patrol.

Each man had a battle station and a watch station, and every enlisted man was expected to qualify in submarines: to learn every system in the boat, compartment by compartment, until he could operate any valve and explain any line, and then to prove it to the officers before he could wear the dolphins insignia. The test was practical, because in a submarine a mistake by one man could sink the boat and kill everyone in it. Discipline was less formal than in a surface ship and the work more demanding; the relationship between the captain and his crew, eighty men who saw him every day, counted for more than in any other kind of warship.

Everything depended on that captain. The commanding officer of a fleet boat, usually a lieutenant commander in his early thirties in 1942, was alone at sea for two months with no one to consult, under orders to maintain radio silence except for contact reports and the end-of-patrol message. He decided whether to attack, how and when, and whether to take the risks that sinking ships required. In the first year of the war, many of the men in command had grown up under the peacetime rules and could not adapt to the war; others, younger and bolder, were waiting for their chance. Sorting one kind from the other was one of the hard jobs of the submarine admirals in 1942 and 1943.

The attack: periscope, plot and Torpedo Data Computer

A torpedo attack was a problem in relative motion. The submarine had to fire a torpedo running at 46 knots, or 31 knots at its slower setting, so that it reached a point in the sea at the same moment as a ship moving at 8 or 12 or 18 knots, perhaps zigzagging, perhaps two or three thousand yards away, with the geometry changing every second. The captain at the periscope supplied the raw data: the target’s bearing, read off the periscope ring; its range, estimated with a stadimeter that measured the angle subtended by the target’s masthead; and its angle on the bow, the angle at which he saw it, which he judged by eye. Sonar gave bearings and, from the count of propeller turns, a rough speed. The executive officer and a plotting party worked the problem on a chart in the control room as a check.

The heart of the system was the Torpedo Data Computer, the TDC, built by the Arma Corporation, an electromechanical analog computer of gears, cams and differentials about the size of a large filing cabinet that stood in the conning tower. The Mark III version fitted to the fleet boats had two halves. The position keeper took the data on the target and on the submarine’s own course and speed and continuously tracked where the target was; once it was set up correctly, its generated bearing matched what the captain saw in the periscope, which was the test that the solution was right. The angle solver then computed the gyro angle each torpedo needed to hit, and fed it automatically to the torpedoes in the tubes, whose gyros were set right up to the moment of firing. No other navy had anything as good. The TDC let a U.S. captain fire on a moving target at large track angles with the boat turning, rather than having to point his whole submarine at the target as the earlier methods and most foreign submarines required.

The attack itself ended with a spread: two, three or four torpedoes fired a few seconds apart, aimed to cover errors in the solution. A good shot was fired at 1,000 to 2,000 yards with the target nearly broadside on, the torpedoes set to run a few feet below the keel so that the magnetic exploder would fire them under the ship and break its back. The system was sound. What failed, as the submarine force would spend nearly two years proving, was the torpedo at the end of it.

The Asiatic Fleet’s lost campaign

Hart’s submarines were the largest striking force the United States had in the western Pacific, and they were expected to make the Japanese pay heavily for any landing in the Philippines. They failed. The Japanese bombed the Cavite Navy Yard on Manila Bay on 10 December 1941 and destroyed it. Sealion (SS-195), under overhaul there, took two bombs; the second smashed through a ballast tank and the pressure hull and exploded in the after engine room, killing four men, the first U.S. submariners to die in the war. She could not be repaired, and on 25 December she was blown up to keep her out of Japanese hands (DANFS). The raid also destroyed 233 Mark 14 torpedoes in storage at Cavite, a loss Blair called avoidable and that weighed on the force for months, though Ransom has argued that most of them would have been lost when Manila fell anyway.

At sea the results were thin. The submarine commander, Capt. John Wilkes, who took over from Capt. Walter Doyle on 10 December, spread his boats in a defensive deployment off the likely landing beaches and along the approaches. Ten boats east and south of Luzon made three attacks by 21 December and sank nothing; seven in the South China Sea made fifteen attacks and claimed four sinkings, of which postwar records confirm one; six off western Luzon sank nothing (Ransom). On 16 December Swordfish (SS-193), out of Manila, sank the Japanese freighter Atsutasan Maru off Hainan, the first Japanese ship sunk by an American submarine in the war (NHHC).

The test came when the main Japanese invasion force entered Lingayen Gulf, on the west coast of Luzon, late on 21 December. Stingray sighted the convoy and reported it but did not attack. Over the next five days six boats tried and failed to get through the antisubmarine screen at the mouth of the gulf; only the old S-38, which slipped into the shallow gulf itself, sank a transport, the Hayo Maru, on 22 December. Seven of Hart’s 29 submarines took part in opposing the landing (Ransom). Wilkes relieved two commanding officers that month. By January he and his captains suspected that the Mark 14 was running deep and that its magnetic exploder was firing too early; the Bureau of Ordnance answered that its rate of premature explosions was within acceptable limits (Ransom). Those suspicions are the beginning of the story told in Chapter 2.

As the Japanese closed on Manila, the submarines became the only link to the garrison on Corregidor and Bataan, the subject of this site’s Bataan and Corregidor collection. Seawolf, Trout and others ran in ammunition and food and carried out key personnel. Trout left Pearl Harbor on 12 January 1942 with about 3,500 rounds of antiaircraft ammunition and reached Corregidor on 3 February; because no sand or concrete was available to replace the weight she unloaded, she took on 20 tons of gold bars and silver pesos from the Philippine treasury as ballast and carried them to Pearl Harbor (DANFS). The Asiatic submarines fell back from Manila to Surabaya in Java, and when the Allied defense of the Netherlands East Indies collapsed in February and March 1942, to Australia.

Pearl Harbor’s first patrols

From Pearl Harbor the first war patrol of the U.S. submarine force began on 11 December 1941, when Gudgeon (SS-211), Lt. Cmdr. Elton W. “Joe” Grenfell, sailed for Japan with written orders to conduct unrestricted submarine warfare. She was the first American submarine to patrol off the coast of the Japanese home islands, off Kyushu. On 27 January 1942, on her way home, she fired three torpedoes at a Japanese submarine; Grenfell claimed only damage, but the codebreakers at Pearl Harbor confirmed the loss of I-73, the first enemy warship sunk by a U.S. submarine in the war. Pollack, Plunger and other boats followed Gudgeon to Japanese waters in December. They found targets in plenty and sank far fewer than they attacked.

On 31 December 1941 Adm. Chester W. Nimitz took command of the Pacific Fleet. There were few ships whose decks were fit for the ceremony at Pearl Harbor that week, and Nimitz, an old submariner, hoisted his flag aboard the submarine Grayling (SS-209) (DANFS). For the first half of 1942 the submarines were almost the only part of his fleet that could carry the war to the enemy’s own waters, and he watched their results closely.

The boats fought in the Pacific Fleet’s battles too, as they had been designed to. At Midway, in June 1942, a dozen submarines were deployed in an arc west of the atoll to ambush the Japanese carriers; most never made contact, and the one that did, Nautilus, attacked the burning carrier Kaga with torpedoes that failed to explode (the record of that attack, long credited as damaging Soryu, was sorted out only after the war). Three weeks later Nautilus, Lt. Cmdr. William H. Brockman Jr., sank the destroyer Yamakaze off the coast of Honshu, and the photograph Brockman took through his periscope, at the head of this chapter, became one of the defining images of the campaign. Submarines also landed and supplied the Marine raiders on Makin in August 1942 and scouted for the carriers.

Withers was replaced as Commander Submarines Pacific Fleet in May 1942 by Rear Adm. Robert H. English. English pushed his boats to Japan, the East China Sea and the Japanese bases in the Carolines and Marianas, but he also kept them on fleet missions and, like the Bureau of Ordnance, was slow to accept that the torpedoes rather than the skippers were at fault. On 21 January 1943 he was killed when the Pan American flying boat Philippine Clipper crashed in the mountains of northern California on the way to San Francisco. His successor, Rear Adm. Charles A. Lockwood, came from Australia.

Fremantle and Brisbane

The Asiatic Fleet’s survivors reached Western Australia in early March 1942. The tender Holland was at Fremantle, the port of Perth, by 5 March with five submarines alongside, and the tender Otus arrived on 10 March; the Asiatic submarine force made Fremantle its base from 1 March. In May Lockwood, newly promoted to rear admiral, arrived to command the submarines of the Southwest Pacific there. He found a force worn out by retreat, short of spare parts and torpedoes and deeply suspicious of its weapons, and in June 1942 he set out to test the torpedoes himself (Chapter 2). A second force, Task Force 42, was formed at Brisbane in Queensland in April 1942 under Capt. Ralph W. Christie, with the tender Griffin and a squadron of old S-boats sent from the Atlantic, later replaced by fleet boats. The Brisbane boats patrolled the Solomons, the Bismarck Archipelago and New Guinea in support of the campaigns there, and it was from Brisbane that Dudley Morton took Wahoo to Wewak in January 1943.

The geography of the submarine war took shape around those bases. From Pearl Harbor, with Midway as a forward fuel stop 1,300 miles to the northwest, the boats patrolled the waters off Japan itself, the Kurils, the Bonins, the East China Sea and the Japanese bases in the Marianas and Carolines, above all Truk. From Fremantle they went north through the Lombok and Makassar Straits to the South China Sea, the Philippines and the oil ports of Borneo and the Indies, through which ran the tanker traffic that kept Japan’s fleet and industry alive. From Brisbane they covered the South Pacific. Each patrol was a round trip of thousands of miles, and the endurance of the fleet boats, designed for a war against the battle fleet, proved ideal for a war against shipping.

Japan’s lifeline

Japan’s war plan depended on shipping as much as any plan in the war. The southern conquests of early 1942, Malaya, the Indies, the Philippines, Burma, were made to secure the oil, rubber, tin and bauxite that the American, British and Dutch embargoes of 1941 had cut off. That oil and ore had to be carried thousands of miles to Japan, past the Philippines and Formosa and up the coast of China, while the outlying garrisons of the new empire, from the Aleutians to the Solomons, had to be supplied by sea as well. Japan entered the war with about 6.4 million tons of merchant shipping, plus about 1.2 million tons in smaller craft (Parillo), and its army and navy requisitioned much of it from the start.

Japan was badly prepared to defend that shipping. Its navy, like the U.S. Navy, had planned for a decisive battle between fleets; escort of merchant convoys was a low priority, and the Imperial Navy had few escorts, little doctrine for convoy and no serious antisubmarine organization until 1943. Japanese merchant ships often sailed alone or in small, weakly escorted groups through the first year. Japanese depth charges, as American submariners would learn from experience, were often set too shallow. A submarine force with good torpedoes and aggressive commanders would have found 1942 a hunting ground. The U.S. force of 1942 had neither in sufficient measure.

By the numbers

Who sank Japan’s merchant fleet, 1941–1945

Japanese merchant ships of 500 gross tons and over sunk by U.S. forces, by sinking agent, in gross tons, as assessed by the Joint Army–Navy Assessment Committee after the war. Number of ships in brackets.

U.S. submarines (1,113 ships)4.78M

Carrier-based Navy and Marine aircraft (359)1.39M

Army aircraft (240)640K

Mines laid by Army Air Forces aircraft (241)567K

Land-based Navy and Marine aircraft (88)219K

Aircraft in combination (23)114K

Surface ships (11)43K

All U.S. forces, all agents (2,117)7.91M

The submarine campaign gathered force slowly. Postwar figures credit U.S. submarines with roughly 725,000 tons of Japanese merchant shipping sunk in December 1941 and 1942 together, about 1.5 million tons in 1943 and about 2.7 million tons in 1944, after which there were few Japanese ships left to sink (JANAC figures as summarized by later historians; the yearly totals vary slightly by source). The first year’s results were enough to hurt but not to cripple: they did not keep Japan from moving its armies, its ore or its oil, and Japanese shipyards and captured Allied ships made up part of the loss. What changed in 1943 and 1944 was not the number of boats alone. It was the torpedo, the commanders and the tactics.

A disappointing first year

By the end of 1942 the submarine force had learned what was wrong, although it had fixed little of it. Its peacetime commanders were often too cautious: they fired from long range, on sonar bearings, from deep submergence, and broke off attacks at the first sign of an escort. The admirals relieved many of them in 1942 and 1943 and gave their boats to younger officers, many of them executive officers who had spent the first year watching their captains fail. Patrol areas were often badly chosen, and boats were kept too long on fleet duties, guarding against Japanese fleet movements that rarely came. And the Mark 14 torpedo, the force’s main weapon, ran too deep, exploded too early and often failed to explode at all, faults that took until the autumn of 1943 to cure (Chapter 2).

There were also too few boats. The Navy had 51 submarines in the whole Pacific at the start of the war, and the new Gatos came slowly at first: Electric Boat at Groton, the navy yards at Portsmouth and Mare Island and, from 1942, Manitowoc Shipbuilding on Lake Michigan, which sent its boats down the Mississippi to the sea on floating dry docks, were only beginning to reach wartime production. Torpedoes were scarcer still. National production in 1939 had been about three torpedoes a day; in the autumn of 1941 the target was 50 a day, and the Naval Torpedo Station at Newport and the torpedo plant at Alexandria between them made 23. Only about 2,000 submarine torpedoes were built in 1942 (figures from Newpower and Rowland and Boyd). Captains were told to fire fewer per target, which made misses more likely, and with no more than 24 torpedoes aboard, a patrol could end early because the torpedoes ran out.

For all that, the foundations were laid in 1942. The submarine bases at Pearl Harbor, Midway, Fremantle and Brisbane were working. The new boats were coming. The SJ radar was going into the fleet, and the TDC was proving its worth. The best of the new commanders were already at sea: Dudley Morton would take Wahoo to Wewak in January 1943, with Richard O’Kane as his executive officer, and at Mare Island the keel of a new Balao-class boat, to be called Tang, was laid on 15 January 1943. Before either could do their work, the submarine force had to make its torpedoes run straight and explode, and to prove to its own Bureau of Ordnance that they did not.

Timeline

The Silent Service goes to war, 1930–1943

1. 22 Apr 1930The London Naval Treaty (Article 22) binds submarines to the rules of cruiser warfare against merchant ships.
2. 6 Nov 1936The London Submarine Protocol restates the rules; the United States is a party.
3. Dec 1940War Plan Rainbow 3 allows fleet commanders to bar merchant shipping from “strategical areas.”
4. Sep 1941Stark and Turner decide to authorize unrestricted submarine warfare against Japan at the outbreak of war.
5. 1 Nov 1941Drum (SS-228), the first Gato-class fleet boat, is commissioned.
6. 7 Dec 1941, 07:55 HawaiiJapanese aircraft attack Pearl Harbor; the submarine base and fuel farm are not seriously hit.
7. 7 Dec 1941, 17:52 EasternStark orders: execute against Japan unrestricted air and submarine warfare.
8. 10 Dec 1941Japanese bombers destroy the Cavite Navy Yard; Sealion is wrecked and four of her crew killed; 233 torpedoes are lost.
9. 11 Dec 1941Gudgeon sails from Pearl Harbor on the first U.S. war patrol of the war, bound for Japan.
10. 16 Dec 1941Swordfish sinks Atsutasan Maru off Hainan, the first Japanese ship sunk by a U.S. submarine.
11. 21–26 Dec 1941Japanese landings at Lingayen Gulf; S-38 sinks the transport Hayo Maru on 22 December, the only success against the invasion fleet.
12. 31 Dec 1941Nimitz takes command of the Pacific Fleet aboard the submarine Grayling.
13. 27 Jan 1942Gudgeon sinks the submarine I-73, the first enemy warship sunk by a U.S. submarine.
14. 3 Feb 1942Trout delivers antiaircraft ammunition to Corregidor and loads 20 tons of gold and silver as ballast.
15. Mar 1942The Asiatic submarines reach Fremantle; Holland is there with five boats on 5 March.
16. Apr–May 1942Task Force 42 forms at Brisbane under Christie; Lockwood takes command at Fremantle; English relieves Withers at Pearl Harbor.
17. 4–6 Jun 1942Battle of Midway: twelve submarines deployed; Nautilus attacks the carrier Kaga.
18. 20–21 Jun 1942Lockwood’s net tests at Albany, Western Australia, show the Mark 14 running about 11 feet deep.
19. 25 Jun 1942Nautilus sinks the destroyer Yamakaze off Honshu and photographs her sinking.
20. 21 Jan 1943Rear Adm. English is killed in the crash of the Philippine Clipper in California; Lockwood succeeds him in February.

Questions readers ask

Why were the Japanese submarines and the American submarines used so differently?

Both navies built large, long-range submarines to fight alongside their battle fleets. The U.S. Navy abandoned that idea within months and turned its boats against shipping; the Imperial Japanese Navy largely kept its submarines on fleet missions, attacking warships and later supplying cut-off garrisons, and made comparatively little effort against American supply lines. Japanese submarines scored notable successes against warships, sinking the carriers Yorktown and Wasp and the cruiser Indianapolis (see this site’s Manhattan Project collection), but never mounted a sustained campaign against Allied shipping.

Was unrestricted submarine warfare legal?

Under the London treaties of 1930 and 1936, read literally, no: a submarine could not sink a merchant ship without first putting its crew in a place of safety. The U.S. position was that Japan’s merchant ships were armed, sailed in convoy, reported submarines and served the Japanese armed forces, and so had lost the protection of the treaty. The Nuremberg tribunal in 1946 found Admiral Dönitz guilty of violating the London Protocol but imposed no sentence on that count, citing the British Admiralty’s orders and Nimitz’s statement that the U.S. Navy had done the same in the Pacific.

Why were the submarines called “boats”?

By naval custom submarines have always been called boats, whatever their size, a holdover from the first small submarine torpedo boats of the 1900s. A Gato-class fleet boat was larger than many destroyers of the First World War, but her crew still called her a boat.

How many U.S. submarines served in the Pacific war?

The force began the war with 51 boats in the Pacific, 22 at Pearl Harbor and 29 at Manila. The shipyards then delivered 77 Gatos and, before the surrender, 108 Balaos, followed by the first of the deeper-diving Tench class, and nearly all of them went to the Pacific, along with the older fleet boats and the S-boats of the 1920s. Fifty-two U.S. submarines were lost from all causes, all but one, Dorado, lost in the Atlantic, in the Pacific war.

Did the submarines really sink more Japanese shipping than the aircraft?

Yes, by a wide margin, in merchant shipping: JANAC credited U.S. submarines with about 4.78 million tons, against about 2.9 million tons for all U.S. aircraft and aircraft-laid mines together. Against warships the aircraft did better, with carrier aircraft credited with about 711,000 tons of Japanese warships to the submarines’ 540,000. In the last months of the war, when few Japanese ships still ventured onto the open sea, aircraft and the aerial mines of Operation Starvation (see the Army Air Forces collection) did most of the remaining damage.

How it connects

This is the first chapter of The Submarine War in the Pacific. It follows directly from the attack described in this site’s Pearl Harbor collection, and the Asiatic Fleet’s failure and the submarine runs to Corregidor belong to the story of Bataan and Corregidor; the U-boat campaign that the American planners studied and then copied is told in the Battle of the Atlantic collection. Chapter 2 takes up the torpedo scandal and the rise of Dudley Morton’s Wahoo in 1943; Chapter 3 begins the story of USS Tang at Mare Island.

Later chapters cross into the site’s other collections: the lifeguard submarines that picked up downed airmen, including B-29 crews off Japan (Chapter 4 and the Army Air Forces collection), the great naval battles of 1944 (Chapter 6), and the end of the war in Tokyo Bay (Chapter 9), which links to the Manhattan Project collection. All are part of the site’s World War II library.

Seeing it today

More than a dozen World War II fleet boats survive as museum ships in the United States. Drum (SS-228), the first Gato and the only one in commission on 7 December 1941, is on display ashore at Battleship Memorial Park in Mobile, Alabama. Bowfin (SS-287), a Balao launched a year to the day after the Pearl Harbor attack, is the centerpiece of the Pearl Harbor Aviation and Submarine Museum and Park beside the Arizona Memorial visitor center at Pearl Harbor, where the Waterfront Memorial lists the 52 lost boats and their men; the bells and relics of several lost boats are kept there. Pampanito (SS-383), with the working TDC shown above, is at the San Francisco Maritime National Park Association on Fisherman’s Wharf, and the association’s website hosts a library of fleet-boat manuals.

Other boats open to visitors include Cod in Cleveland, Silversides in Muskegon, Cobia at the Wisconsin Maritime Museum in Manitowoc, where she was built, Cavalla in Galveston, Batfish in Muskogee, Croaker in Buffalo, Becuna in Philadelphia, Torsk in Baltimore, Lionfish in Fall River and Razorback in North Little Rock. The Submarine Force Museum at Groton, Connecticut, home of the Submarine Force Library, holds the Navy’s official submarine collection. The submarine base at Pearl Harbor is still in service, now part of Joint Base Pearl Harbor–Hickam and not open to the public.

Sources

• Clay Blair Jr., Silent Victory: The U.S. Submarine War Against Japan (Philadelphia: J. B. Lippincott, 1975; Naval Institute Press reprint, 2001).
• Joel Ira Holwitt, “Execute Against Japan”: The U.S. Decision to Conduct Unrestricted Submarine Warfare (College Station: Texas A&M University Press, 2009).
• Richard B. Frank, review of Holwitt, World War II magazine, November 2009, HistoryNet.
• James P. Ransom III, “Bleak December,” Naval History, December 2021, U.S. Naval Institute.
• Joint Army–Navy Assessment Committee, Japanese Naval and Merchant Shipping Losses During World War II by All Causes (Washington: Government Printing Office, 1947), summary tables at HyperWar.
• Theodore Roscoe, United States Submarine Operations in World War II (Annapolis: U.S. Naval Institute, 1949).
• Norman Friedman, U.S. Submarines Through 1945: An Illustrated Design History (Annapolis: Naval Institute Press, 1995).
• John D. Alden, The Fleet Submarine in the U.S. Navy: A Design and Construction History (Annapolis: Naval Institute Press, 1979).
• Mark P. Parillo, The Japanese Merchant Marine in World War II (Annapolis: Naval Institute Press, 1993).
• Anthony Newpower, Iron Men and Tin Fish: The Race to Build a Better Torpedo during World War II (Westport: Praeger, 2006); Buford Rowland and William B. Boyd, U.S. Navy Bureau of Ordnance in World War II (Washington: Bureau of Ordnance, 1953).
• Samuel Eliot Morison, History of United States Naval Operations in World War II, vol. 3, The Rising Sun in the Pacific, and vol. 4, Coral Sea, Midway and Submarine Actions (Boston: Little, Brown, 1948–1949).
• Naval History and Heritage Command, Dictionary of American Naval Fighting Ships: Sealion, Trout, Grayling; Swordfish (SS-193).
• Naval History and Heritage Command, “Chester William Nimitz,” biography.
• U.S. Navy, The Fleet Type Submarine, NAVPERS 16160 (1946), and Submarine Torpedo Fire Control Manual, ORD 2 (1950), online at the Maritime Park Association.
• Commander, Submarine Force, U.S. Pacific Fleet, “SUBPAC History” (official history page).
• “List of United States Navy ships present at Pearl Harbor, 7 December 1941,” compiled from NHHC records (consulted for the submarines in port).

Photographs: U.S. Navy photographs in the National Archives (80-G and other series, including two by Edward Steichen’s naval photographic unit) and the Naval History and Heritage Command, a U.S. Navy recruiting poster in the National Archives, and an Australian armed forces photograph in the Australian War Memorial collection, all public domain; a modern photograph of the Torpedo Data Computer aboard USS Pampanito by a Wikimedia Commons contributor (CC BY-SA 3.0); all via Wikimedia Commons. Archival identifications of boats and dates are given as recorded, with uncertainties noted. The badge drawn for this collection is an illustration, not an official emblem.