Named for the sea lion, any of several large, eared seals native to the Pacific.
The second Sealion (SS-315) was laid down on 25 February 1943 by the Electric Boat Co., Groton, Conn.; launched on 31 October 1943; sponsored by Mrs. Emory Land; and commissioned on 8 March 1944, Lt. Comdr. Eli T. Reich in command.
Following the shakedown, Sealion, assigned to Submarine Division (SubDiv) 222, sailed for the Pacific and arrived at Pearl Harbor on 17 May. Further training occupied the next three weeks; and, on 8 June, she headed west on her first war patrol. Sailing with Tang (SS-306), she stopped off at Midway on the 12th; glanced off a whale on the 15th; and, on the 22d, transited Tokara Strait to enter the East China Sea. On the 23d, she and Tang took up stations in the Osumi Gunto, an island group to the south of Kyushu. That afternoon, Sealion unsuccessfully conducted her first attack; then underwent her first depth charging.
On the 24th, Tinosa (SS-283) joined the two submarines; and the group moved northward to patrol the approaches to Sasebo. Patrolling in adjacent lanes, the submarines contacted a convoy on the 25th, but Sealion lost depth control on reaching attack position and was unable to fire.
From the Sasebo area, the submarines moved toward the Korean peninsula. On the 28th, Sealion caught and sank a Japanese naval transport, Snasei Maru, in the Tsushima Island area; then continued on into the Korean archipelago. On the 30th, she used her deck guns to sink a sampan; and, with the new month, July, she moved closer to the China coast to patrol the approaches to Shanghai.
On the morning of 6 July, Sealion intercepted a convoy south of the Four Sisters Islands and, at 0447, commenced firing torpedoes at two cargomen in the formation. Within minutes, the 1,922-tpn Setsuzan Maru sank, and the convoy scattered. Sealion retired to the northeast to evade the convoy's escort, a destroyer, as it began its search for the submarine. At 0600, the destroyer closed Sealion; and the submarine fired four torpedoes at the warship. All missed. An hour later, enemy aircraft joined the search which was continued until mid-afternoon.
Three days later, Sealion moved northward again and commenced hunting between the Shantung peninsula and Korea. Dense fog blanketed the area and left her blind while her radar was out of commission. By midnight on the night of 10 and 11 July, however, her radar was back in partial operation; and, on the morning of the 11th, she conducted several attacks, sinking two freighters, Tsukushi Maru No. 2 and Taian Maru No. 2.
The running surface chase with the second freighter involved three attacks over a period of almost seven hours. On the third attack, at 0711, Sealion fired her last torpedo; then, after debris from the explosion had flown over the submarine, she moved down the port quarter of the target, pouring 20mm. shells into the Japanese bridge. At 0714, the freighter disappeared; and Sealion headed south of Tokara Strait. On the 13th, she cleared that strait; and, on the 21st, she arrived at Midway.
Refitted by Fulton (AS-11), Sealion departed for the Bashi Channel and her second war patrol on 17 August. Hunting with Growler (SS-215) and Pampanito (SS-383), she transited the channel and moved into the South China Sea on 30 August. During the pre-dawn hours of the 31st, she conducted a night surface attack against a Japanese convoy and heavily damaged a tanker. As Rikko Maru bellowed black smoke, other Japanese ships took Sealion under fire with deck guns. The submarine moved out of the area and ahead of the convoy. At 0720, she again attacked the convoy. Within minutes, Shirataka, a minelayer, went down; enemy planes begin circling the area; and the convoy's surface escorts began their search. Sealion went deep and headed south. Later that day, she closed another target with a merchant ship appearance; but, as she reached firing position, the target was made out to be an antisubmarine vessel. Three torpedoes were fired, but were spotted by the target's bow lookout. The target swerved, and the hunter became the hunted. Depth charging followed without damage to the submarine; but Sealion, low on fuel and torpedoes, headed for Saipan.
There, the submarine rearmed and refueled; and, on 7 September, got underway to rejoin her attack group. On the 10th, she moved through Balintang Channel. On the llth, she rendezvoused with two other submarines; and, on the 12th, the group attacked and decimated a convoy en route to Formosa.
At about 0200, Growler attacked the formation. Pampanito and Sealion followed suit. Growler's torpedoes sent a destroyer to the bottom. Sealion fired two torpedoes, both misses, and was taken under fire by two of the escorts. The submarine went to top speed and managed to keep ahead of the escorts until they broke off to rejoin the convoy shortly before 0330.
An hour and one-half later, Sealion again closed the convoy and, at 0522, fired three torpedoes at a tanker; then swung to fire on a large transport, Rakuyo Maru, the last ship in the nearer column. At 0524, the tanker Zuiho Maru, possibly hit by torpedoes from both Pampanito and Sealion, burst into flames. Kachidoki Maru, a transport near the tanker, was disabled. She swung into the burning tanker and was soon ablaze. Sealion's second target was illuminated; and, at 0525, she fired on Rakuyo Maru. Both torpedoes hit and that ship began to burn.
Sealion was then forced deep and, after several attempts to get a better look at the scene, cleared the area and started after the remainder of the convoy.
On the morning of the 15th, the three submarines reformed their scouting line. That afternoon, Pampanito radioed Sealion, and other submarines in the area, to return to the scene of the action on the 12th. Rakuyo Maru had been carrying Australian and British prisoners of war. By 2045, Sealion had taken on 54 POW's and started back to Saipan. All of the POW's were coated with crude oil and all were in poor health, suffering from malaria, malnutritional diseases such as pellagra and beriberi, and exposure. Three died before the submarine reached Balintang Channel on the 17th. On the 18th, Case (DD-370) rendezvoused with Sealion and transferred a doctor and a pharmacist's mate to the submarine. On the 19th, a fourth POW died; and, on the 20th, Sealion arrived in Tanapag Harbor and transferred the surviving 50 to the Army hospital there.
Prom Sainan, Sealion returned to Hawaii. Arriving at Pearl Harbor on 30 September, she departed again on 31 October and, with Kete (SS-369), headed west to patrol in the East China Sea. The two submarines stopped off at Midway on 4 November; then continued on to their patrol area.
Ten days later, Sealion transited Tokara Strait. On the 16th, her number 8 tube was accidentally fired with both doors closed. Heavy seas prevented a thorough inspection of the damage. On the 17th, she began patrolling the approaches to Shanghai. On the 18th, there was a hydrogen explosion in the battery space of the torpedo in number 5 tube. On the 21st, at 0220, she made radar contact with an enemy formation moving through Formosa Strait at about 16 knots and not zig-zagging.
By 0048, the pips were made out to be two cruisers and two battleships. At 0146, three additional ships, escorts-one on either beam of the formation and one on the starboard quarter-became visible. At 0245, Sea lion, ahead of the task force, turned in and slowed for the attack. Eleven minutes later, she fired six torpedoes at the second ship in line. At 0259, she fired three at the second battleship. At 0300, her crew saw and heard three hits from the first salvo, but they had hit and sunk the destroyer, Urakaze, not the first battleship. Shortly thereafter, one torpedo from the second spread hit the second battleship. Sealion opened to the westward. The Japanese searched to the east. By 0310, the submarine had reloaded and began tracking again with the thought that the torpedoes had only dented the battleship's armor belt.
The enemy formation, however, had begun zigzagging and the sea and wind had increased; then, at 0450, the enemy formation split into two groups. Sealion began tracking the slower group, the apparently damaged battleship escorted by two destroyers. At 0524, a tremendous explosion lit the area and the battleship, Kongo, disappeared.
During the next few days, Sealion continued to patrol between China and Formosa; and, on the 28th, she headed for Guam.
On her fourth war patrol, 14 December to 24 January 1945, Sealion returned to the South China Sea in a coordinated attack group with Blenny (SS-324) and Caiman (SS-323). Poor weather plagued her; and, of the 26 days spent on station, all but six were spent on the surface. On one of those few good days, 20 December, she sighted a supply ship escorted by a destroyer through her high periscope and, at 1937, fired six torpedoes at the supply ship for four hits. The submarine then evaded the escort, reloaded, and waited. Two and one-half hours later, the target, Mamiya, was still afloat, and the submarine went in for a second attack. At 0032 on the 21st, she fired three torpedoes for two hits. The supply ship went under.
That day, Sealion joined the 7th Fleet; and, from 28 December 1944 to 14 January 1945, she performed reconnaissance duties in support of the reoccupation of the Philippines. On the latter date, she cleared her patrol area and headed for Western Australia.
Arriving at Fremantle on the 24th, she departed on her fifth war patrol on 19 February. Again operating in a coordinated attack group, she returned to the South China Sea; then proceeded into the Gulf of Siam. In the predawn darkness of 17 March, she torpedoed and sank a small unescorted tanker, Samui; and, on 2 April, she rescued an Army aviator who had been drifting in a rubber raft for 23 days. That same day, three more downed aviators were transferred to her from Guavina (SS-362) ; and, on the 6th, she delivered her passengers to Subic Bay.
By 30 April, Sealion was again ready for sea. With Bashaw (SS-241) and Hammerhead (SS-364), she departed Subic Bay for the northern part of the South China Sea. Through May, she patrolled off Hong Kong and provided lifeguard services for strikes against Formosa. At the end of the month, she received downed aviators from Bream (SS-243) and transported them back to Subic; then, with passengers bound for Hawaii, she sailed east. On 12 June, she arrived at Guam, whence she proceeded to a lifeguard station off Wake Island; and, on 30 June, she cleared that area for Pearl Harbor.
From Pearl Harbor, Sealion continued on to San Francisco where she was undergoing overhaul at the end of the war. With the cessation of hostilities, in-activation preparations were added to the overhaul; and, on 2 February 1946, the submarine, which had been awarded the Presidential Unit Citation for her six war patrols, was decommissioned.
A year and one-half later, however, Sealion, along with Perch (SS-313), was designated for conversion to a troop carrier; and, in April 1948, she entered the San Francisco Naval Shipyard for the eight-months conversion. During that period, her torpedo tubes and forward engines were removed; and her forward engine room and forward and after torpedo rooms were converted to berth 123 troops. The forward engine room and after torpedo room were designed for alternative use as cargo space. The wardroom was redesigned for use as an operating room; the beam aft of the conning tower was extended; and a large watertight cylindrical chamber was installed abaft the conning tower to store amphibious landing equipment, including an LVT.
On 2 November 1948, Sealion was recommissioned with the hull designation SSP-315. Training exercises off the southern California coast, with Marines embarked, took her into the spring of 1949 when she was ordered to the Atlantic for duty in SubDiv 21. During April, she operated in the New London area; then, in May, she commenced operations out of Norfolk as a unit of SubDiv 61, SubRon 6. On 31 January 1950, she was reclassified ASSP-315; and, by the spring of that year, had conducted exercises as far north as Labrador and as far south as the southern Caribbean. Prom April through June of 1950, she underwent her first post-conversion overhaul at Portsmouth, N.H.; and, in July, she resumed operations out of Norfolk.
Reassigned to SubDiv 63 in March 1955 and re-classified APSS-315 on 24 October 1956, Sealion continued a schedule of exercises with Marines, Underwater Demolition Teams and Beaehjumper units; and, on occasion, Army units, off the Virginia and Carolina coasts and in the Caribbean until 1960. During that time, interruptions came only for overhaul periods, during one of which the -LVT hangar- abaft the conning tower was removed, and for one deployment with the 6th Fleet in the Mediterranean from August to November 1957.
On 30 June 1960, Sealion was decommissioned at Portsmouth, N.H., where she remained as a reserve training submarine until reactivated a year later. In August 1961, she was towed to Philadelphia for overhaul; on 20 October, she was recommissioned; and, on 18 December, she rejoined SubRon 6 at Norfolk. There she resumed a schedule similar to that of the 1950's, again with few interruptions, for regular overhauls, and, in the fall of 1962, to support the blockade put into effect during the Cuban Missile Crisis. On 22 October 1962 she departed Norfolk on what was to be a month-long training cruise in the Caribbean, but the formation of the blockade force altered the cruise plans. On 3 December, she returned to Norfolk and from then into 1967 she maintained her schedule of exercises with Marine Reeconnaissance, UDT, and SEAL personnel. On 15 September 1967, she changed homeports and administrative control and for the next two years, her last two years of active service, she operated out of Key West as a unit of SubDiv 121. Reclassified LPSS-315 in January 1969, Sea lion was ordered inactivated the following summer; and, in September, she proceeded to Philadelphia where she was decommissioned and placed in the inactive fleet on 20 February 1970.
Sealion (SS-315) earned five battle stars during World War II.