| Acronym | Meaning |
| SSI | Scuba Schools International; Diving Instruction Organization. |
| DM | Dive Master (PADI) |
| IAND | International Association Of Nitrox Divers |
| OWIC | Open Water Instructor Course (BSAC) |
| MSDT | Master SCUBA Diver Trainer (PADI) |
| SWP | Safe Working Pressure |
| ITW | Instructor Training Workshop (BSAC) |
| NAUI | National Association Of Underwater Instructors |
| MDL | No Decompression Limit |
| AAS | Alternate Air Source |