Type 037-class (Hainan)

The Type 037 is a series of submarine chasers and missile boats developed for the People's Liberation Army Navy (PLAN) to replace Soviet S.O.-1 class vessels. The series includes the Hainan-class submarine chaser, the Haiqing-class follow-on, and the Houxin and Houjian-class missile boats. While the base design entered production in the 1960s, later variants were developed through the 1990s. The Type 037II design originated from an American proposal but was modified by China to utilize domestic engines and missile systems following 1989.

The class serves as a patrol platform for territorial waters, with variants optimized for anti-submarine or anti-ship warfare. Early units used hull-mounted sonars, which were superseded by the domestic SJD-3 system. This system utilizes a telescoping arm to lower the sonar beneath the hull, reducing noise interference and increasing detection range. Later sub-classes integrated variable depth sonar (VDS) and anti-submarine rocket launchers. Missile boat variants replace anti-submarine equipment with anti-ship missiles and utilize electro-optical targeting systems equipped with infrared seekers and laser rangefinders. The Type 037II variant specifically utilizes tracking and search radars for fire control.

The PLAN has commissioned over 100 units across all variants. In January 1974, two Hainan-class boats participated in naval clashes with South Vietnamese forces at Yongxing Island. Type 037II vessels currently serve as the naval defense force stationed in Hong Kong. International operators of the class include the navies of Bangladesh, Egypt, North Korea, Pakistan, Myanmar, Sri Lanka, and Yemen. Operational losses include a North Korean vessel lost off Wonsan in 2013 and a PLAN vessel, the Lianjiang, which sank after a collision in 2006 but was subsequently refloated. As newer corvettes enter service, the PLAN is decommissioning the Type 037 series, with several units preserved as museum ships in locations such as Jieshou and Shanghang County.