A patrol vessel is relatively small and fast. Most are used by police and government agencies.
Patrol vessels are equipped for patrol, control and surveillance duty. However, they also perform search and rescue, and undertake humanitarian missions during disasters.
Patrol vessels are fast and maneuverable. They have powerful engines and surface-piercing propellers. They also may carry medium-range arms and other military equipment.
Choice will depend on vessel dimensions, engine type and power, range, etc.