| Acronym | Meaning |
| MCS | Marine Conservation Society |
| DL | Dive Leader (BSAC) |
| PPB | Peak Performance Bouyancy |
| ABT | Actual Bottom Time |
| NI | National Instructor (BSAC) |
| CAGE | Cerebral Arterial Gas Embolism |
| PADI | Professional Association Of Diving Instructors |
| HSE | Health And Safety Executive |
| ROV | Remotly Operated Vehicle |
| AMDT | Adjusted Maximum Dive Time |