P
- PB: Patrol boat
- PBR: Patrol boat, River
- PC: Coastal Patrol, originally Sub chaser
- PCE: Patrol Escort
- PCER: Patrol Escort, Rescue
- PCF: Vietnam Swift boat
- PCSC: Patrol Craft, Submarine Chaser
- PCV: Primary Control Vessel
- PE: Eagle boat of World War I
- PF: World War II frigate, based on British River class.
- PFG: Original designation of USS Oliver Hazard Perry (FFG-7)
- PG: Gunboat, later Patrol combatant
- PGH: Patrol Combatant, Hydrofoil
- PHM: Patrol, Hydrofoil Missile
- PM: Monitor
- PR: Riverine gun ship
- PY: Sea-going gun ship
- PT: Motor Torpedo Boat (World War II)
Read more about this topic: List Of Hull Classifications