| Abbreviation | Definition |
|---|---|
| MS | MineSweeper |
| MSA | MineSweeper, Auxiliary |
| MSB | MineSweeping Boat |
| MSC | MineSweeper, Coastal |
| MSCO | MineSweeper, Coastal, Old |
| MSD | MineSweeping Drone |
| MSF | Fleet Minesweeper (MineSweeper, Fleet) |
| MSI | MineSweeper, In-shore |
| MSL | MineSweeping Launch |
| MSM | MineSweeper, LCM conversion |
| MSO | Ocean Minesweeper (MineSweeper, Ocean) |
| MSR | River Minesweeper (MineSweeper, River) |
| MSS | Special Minesweeper (MineSweeper, Special) |
| MSSB | Mine-Sweeping Shrimp Boat |
| MT | Motor Tanker |
| MTB | Motor Torpedo Boat |
| MUV | Multiuse Vessel |
| MV | Merchant Vessel |
| N/S | Nuclear Ship |
| NAABSA | Not Always Afloat But Safe Aground |