| Acronym | Meaning |
| PPB | Peak Performance Bouyancy |
| AD | Adventure Diver (PADI) Advanced Diver (BSAC) |
| PSI | Pounds Per Square Inch |
| OWIC | Open Water Instructor Course (BSAC) |
| DL | Dive Leader (BSAC) |
| ITC | Instructor Training Course (BSAC) |
| RD | Rescue Diver (PADI) |
| RYA | Royal Yachting Association |
| BT | Bottom Time |
| ITS | Instructor Training Scheme (BSAC) |