Shantou - class gunboat The " Shantou " - class gunboat , was a Chinese built gunboat of the People ' s Republic of China ' s People ' s Liberation Army Navy . Known in the United States as the " Swatow " class gunboat ; it was based on the Soviet P - 6 class torpedo boat . The boat is designated as Type 55A ( 55 Jia Xing , 55甲型 ) . Instead of being wooden hulled , and consisting of torpedoes as the main armament , the " Shantou " class is steel - hulled , with guns as the main armament . The " Shantou " ( or " Swatow " ) is the predecessor of the Type 062 class gunboat , or more commonly known as the Shanghai - I & II class . Service history . Entering service from 1955 through 1960 , these vessels were completely removed from naval service by the mid - 1990s , and were transferred to civilian law enforcement agencies . However , just like the " Beihai " , " Huangpu " , and " Yulin " class gunboats which had been transferred to law enforcement agencies , these obsolete and aging boats were not satisfactory in their new civilian roles , due largely to their low maximum speed ( 10 knots ) , which was not sufficient enough to catch the smugglers ' high speed motorboats . As a result , these boats were subsequently transferred again , this time to the reserves ; or subordinated to naval militias in various Military Maritime Districts in China as training boats , or harbor patrol boats . Like the aforementioned gunboats before it , the " Swatow " class , arriving for its new role ( s ) will likewise see increased conversions , some mothballing , and then eventually being scrapped . Again , as with previous units ( vessels ) , many of the surviving boats are being converted to naval auxiliaries , such as firing ( gunnery ) range support craft , target control boat ( remote controlling of target drones ) , as well as being target drones themselves . It is interesting to note , that despite the small amount of scientific instruments they carried , that most of the range support boats in the PLAN also shoulder the responsibility of inshore surveying , regardless of their limitations . Originally , the majority of the hydrographic surveys had been conducted by civilian fishing vessels which had additional scientific equipment , naval and governmental crews onboard . However , since the Chinese economic reform , and the depletion of the fishery resources , the civilian fishing vessels must venture much further out into open ocean on extended voyages , thus were no longer available for coastal or inland water survey operations . Duties which had previously been assigned under the planned economy era in China prior to the economic reform . Consequently , the Chinese Navy must come up with their own solutions to meet these new demands , and the conversion of obsolete gunboats was one of the answers : although many of these vessels can no longer venture into the open sea , nor reach the speeds that they once could , they are still reliable enough to perform the duties of low speed inshore surveying tasks within the confines of river mouths and bays of Chinese coastlines . Contrary to the commonly held , but erroneous belief that the Chinese Navy is following the tradition of maintaining weaponry on many of its auxiliaries ( though there is certainly some degree of this ) , the retention was primarily for economic reasons : to avoid conversion costs , the original armament ( s ) were retained unless they were no longer serviceable . Consequently , many of the range support , surveying boats , and other auxiliary craft still maintain some of their former fighting capabilities .