The PT-11-class, PT-15 (PT-815) was the fifth and final boat of its class, built in 1974–1975 under the 4th Defense Plan as the JMSDF's next-generation torpedo boat. Building on the PT-10 and ASH No.6 prototypes, the class introduced a deep-V aluminium-alloy hull and the JMSDF's first CODAG propulsion system, combining two diesel engines and two gas turbines across three shafts to achieve a top speed of 40 knots. Armed with four 53 cm torpedo tubes and two Bofors 40 mm guns, PT-815 was commissioned in 1975 and ultimately served with the Ominato and Maizuru districts before being retired in 1994.

It was introduced in Update 1.89 "Imperial Navy". As a torpedo motor boat, the PT-815 is one of the most advanced Japanese patrol vessels, second only to the PG-822. It has a high speed, a powerful armament, and excellent torpedoes. The Type 72 torpedo is its main weapon, capable of reaching 120 km/h and delivering 300 kg TnTe to targets up to 10 km away. This makes the PT-815 very effective against larger ships at medium and long distances. The vessel also has two 40 mm Bofors guns, which offer decent firepower but have a lower rate of fire than the Bofors-Breda variant used by the Freccia-class and Jaguar-class PTs.