 They first entered service in the 1960s, but had been completely taken out of active service by the late 1990s, and were transferred to law enforcement agencies.However, just like the Shantou, Huangpu and Beihai classes that were transferred for law enforcement adaptation, these obsolete and aging boats were not satisfactory in their new roles due to their low maximum speed, sometime as low as 10 knots, which was not sufficient to catch the smugglers' high-speed motorboats.As a result, these boats were subsequently transferred again, this time to reserves, subordinated to naval militia in various Military Maritime Districts in China as training boats and port security and patrol boats within the confines of the harbors.