| Acronym | Meaning |
| NITROX | Any Gas Mixture Of Nitrogen And Oxygen; Though Most Commonly Used For Oxygen Mixtures Above The Normal 21 Per Cent. |
| OW(D) | Open Water (Diver) (PADI) |
| IOC | Instructor Orientation Course (PADI) |
| HSE | Health And Safety Executive |
| RDP | Recreational Dive Planner |
| SAR | Search And Rescue/Recovery |
| DM | Dive Master (PADI) |
| SSI | Scuba Schools International; Diving Instruction Organization. |
| DIN | Deutsches Insitut Fuer Normung |
| IDEA | International Diving Educators Association; Diving Instruction Organization. |