Japanese minelayer Hatsutaka

 was the lead vessel in the of medium-sized minelayers of the Imperial Japanese Navy, which was in service during World War II. She was designed as an improved version of anti-submarine netlayer. However, during the Pacific War, due to the critical shortage of escort patrol ships, she was fitted with depth charge racks, her minelaying rails were removed, and she was used primarily for convoy escort duties.
She was sunk in action by , losing 70 men.
Background.
Under the "Maru-3" Supplemental Naval Amaments Budget of 1937, the Imperial Japanese Navy authorized a two vessels of a new class of minelayer (Project number H12) primarily for coastal duties. The new vessel was designed to carry either 100 Type 5 naval mines, or to function as a netlayer based on design features developed through operational experience with "Shirataka".
"Hatsutaka" was launched by the Harima Shipyard near Kobe on 28 April 1939, and was commissioned into service on 31 October 1939.
Operational history.
After commissioning, "Hatsutaka" was assigned to the IJN 1st Fleet’s Second Base Force, but was reassigned to the IJN 3rd Fleet in April 1941, and to the Southwest Area Fleet's First Southern Expeditionary Fleet's Ninth Base Force based at Camranh Bay, French Indochina in October 1941.
After the attack on Pearl Harbor in December 1941, "Hatsutaka" was assigned to ”Operation T”, (the invasion of Sumatra), escorting 11 transports with the IJA 229th Infantry Regiment from French Indochina to Bangka and Palembang on 11 February, and the Imperial Guards Division from Singapore to northern Sumatra on 10 March. This mission was followed by ”Operation D” (the invasion of the Andaman Islands at the end of March, with "Hatsutaka" escorting a convoy from Singapore to Port Blair and Rangoon in Burma. "Hatsutaka" spent the remainder of 1942 and first half of 1943 based at Ambon in the Netherlands East Indies, operating between Ambon and Makassar.
On 15 July 1943 "Hatsutaka" rendezvoused with German submarine "U-511", carrying Vice Admiral Nomura Naokuni, Japan's representative to the Axis Tripartite Commission in Berlin since 1941, and Major Sugita Tamotsu of the IJA Medical Service, Dr. Ernst Wörmann, ambassador to Wang Jingwei's pro-Japanese Reorganized National Government of China and Martin Spahn, leader-designee of the NSDAP (Nazi) party in Japan and three engineers from U-boat builder AG Weser at Bremen "Hatsutaka" escorted the German submarine to Penang. For the remainder of 1943 and first half of 1944, "Hatsutaka" operated along the Sumatra coast between Padang, Medan, and Sabang.
On 19 April 1944 "Hatsutaka" was at Sabang when raided as part of Operation Cockpit, the first combined operation between the Royal Navy, Royal Australian Navy, French Navy, Royal Netherlands Navy, Royal New Zealand Navy, and United States Navy. Forty-six bombers (17 British, 29 American) and 37 fighters (13 British, 24 American) from and raided Sabang, lightly damaging "Hatsutaka", killing three crewmen and wounding five others. "Hatsutaka" was repaired at Singapore, and subsequently performed escort patrol duties between Singapore and Port Blair. On 3 August 1944, "Hatsutaka" struck a mine laid by and was damaged.
Lieutenant Commander Ozaki Sakan assumed command of the Hatsutaka in October, 1944. On 13 January 1945 Hatsutaka participated in a 14-hour attack on with three other ships that rendered HMS "Strongbow" unfit for further service.
On 2 May 1945 "Hatsutaka" was escorting a tanker when attacked by and . At 2249, "Hatsutaka" detected "Baya" with her Type 22 radar and began closing. 2305, "Baya" fired two torpedoes at "Hatsutaka", with both missing. At 2307, "Hatsutaka" opened fire on "Baya" with "20mm, 40mm, and 2 or 3 4.7 inch guns at a range of 1100 yards." and noted at 2308 that "Jap gunnery poor but plenty of it. Tracers passing down both sides of the periscope shears and overhead. 4.7 inch appeared to be both common and fused, as it was ricochetting [sic] alongside and over the stern as well as bursting overhead which was thought at first to be starshells." At 2309, "Baya" fired another three torpedoes, with "Hatsutaka" combing the tracks. When "Hatsutaka" turned on the searchlight at 2320, "Baya" submerged and fired another torpedo at her, missing again. At 2325, when "Baya" surfaced, she secured the searchlight and again commenced firing on "Baya" and dropped six depth charges at 2329, shaking "Baya" violently. At 2333, the range opened and "Baya" informed "Lagarto" that she had been driven off by the escort's gunfire. "Baya" noted that "It is nothing short of a miracle that we came through so much gunfire without a single hit. His deflection was as consistently on as his range was off." 
"Lagarto" made contact with the convoy in a submerged attack at 1400 on 3 May. Japanese records indicate that "Hatsutaka" depth charged and sank "Lagarto" on 3 May. On 3 May at 2215 "Baya" again attempted to attack the convoy, but her own 10 cm radar was detected, alerting the convoy, which commenced evasive maneuvers. At 0011 on 4 May "Baya" fired six torpedoes, with no hits. At 0013, the convoy turned away, with "Hatsutaka" chasing "Baya" as she tried to get in another position to attack.
On 14 May "Hatsutaka" was escorting "Tottori Maru". At 0737, fired five torpedoes at a ship misidentified as "Yaeyama", but missed. At 0745, "Hatsutaka" dropped six depth charges, followed by four more at 0755. At 1147, "Hatsutaka" sighted the periscope of "Cobia", and launched nine depth charge runs, causing severe damage." At 1430, attacked "Tottori Maru", but she evaded three torpedoes, and later that night at 2300, when "Hammerhead" was trying to get another shot in on "Tottori Maru", "Hatsutaka" was always in the way. At 0021 on 15 May "Hatsutaka" opened fire on "Hammerhead", scoring several near misses. "Hatsutaka" then returned to Singapore.
At 0523 on 16 May in rainy weather, fired six torpedoes at "Hatsutaka", two of which hit, flooding her engine room. At 1044, "Hawkbill" fired three more torpedoes. "Hatsutaka" opened fire, but one torpedo struck amidships, causing an explosion, which broke her in half. "Hatsutaka" sank at at 11:15, with 70 crewmen killed in action.
"Hatsutaka" was removed from the navy list on 10 August 1945.
Wreckage.
On March 28, 2008 northwest of Pulau Tenggol, Malaysia a team of divers located "Hatsutaka" about one kilometer off shore.