January 31, 1945 – American submarine chaser PC-1129 intercepted Japanese Shinyo special attack boats in the Philippine Islands, but she was in turn rammed by one of the boats and was sunk. USS PC-1129 was a PC-461-class submarine chaser built for the United States Navy during World War II. The Japanese Navy began working on special attack boats in the spring of 1944. The Navy development program fell under the jurisdiction of the 4th Section (Ship Construction) of the Navy Technical Department at Yokosuka, Japan under the command of Captain S. Makino. The design was kept very simple so they could be built in large numbers. After two prototype forms, six steel prototypes, and two wooden prototypes, the first production example of the Shinyo (“Quaking Sea”) Type 1 crash boats was completed on 27 May 1944. Shinyo Type 1 Mod 1 design was released very shortly after, without transmissions to save costs. Unlike most purpose-built special attack weapons, some Shinyo special attack boats were equipped with rocket launchers for additional firepower during the approach. They first saw combat in the Philippine Islands in the fall of 1944. Around the same time, Shinyo Type 5 boats went into parallel construction. Type 5 boats had two engines for greater speed and machine guns for greater firepower; these boats were meant to lead Type 1 boats in attacks. The first Shinyo special attack boats were based in Sasebo, Japan, organized into squadrons each with about 200 men and 48 boats. They were soon dispatched to the Bonin Islands and the Philippine Islands. The first Shinyo mission ended in disaster as one of the boats accidentally detonated, spreading fire to nearby vessels, effectively wiping out one of the Shinyo Squadron 9 units. When the Iwo Jima, Japan invasion took place in Feb 1945, the Japanese Navy had two Shinyo squadrons on the island, but they were overwhelmed by the pre-invasion bombardment and they were generally ineffective. At Kerama Retto in the Ryukyu Islands southwest of Okinawa, the Shinyo boats under the command of the 5th Sea Raiding Base Headquarters were also ineffective; in fact, most of the 250 boats deployed there were scuttled by their own crew as they could not get the opportunity to launch missions. On Okinawa, both Navy and Army special attack boats got their chances to attack, sinking landing ship LSM-12 on 31 Mar 1945 and gunboat LCI(G)-72 on 3 Apr; nevertheless, far more Shinyo and Renraku-tei boats were destroyed than the number that got through American picket lines. The Japanese Navy had planned to build 7,000 Shinyo special attack boats by Sep 1945; when the war ended, 6,200 were actually built. At the end of the war, 1,249 boats were deployed in the Japanese home islands, while an additional 900 were kept in reserve.