A patrol ship, also known as a patrol boat or coast guard cutter, is a naval vessel that is designed for the purpose of patrolling a particular area. There are several synonyms for the term 'patrol ship' depending on the type and size of vessel and its specific function. These synonyms include offshore patrol vessel, coastal patrol vessel, river patrol vessel, anti-submarine patrol vessel, fast patrol boat, and minehunter- these are just a few examples. The term 'warship' can also be used to refer to a patrol ship designed for military purposes. Regardless of its name, a patrol ship is essential for the protection of a nation's coastal waters and its citizens.