Public service vessels are professional vessels primarily used for law enforcement, patrol and surveillance, emergency rescue, maritime management, border inspection, and environmental protection in inland rivers, lakes, coastal, offshore, and jurisdictional waters, covering inland waterways, coastal ports, and key maritime areas; Major vessel types include patrol ships, fishery administration vessels, border patrol boats, maritime law enforcement vessels, environmental monitoring ships, and police boats, with primary power requirements ranging from 200 kW to 5000 kW. Weichai's compatible engine models include the WP, WH, and M series, with fuel types primarily being diesel.