| Acronym | Meaning |
| SSI | Scuba Schools International; Diving Instruction Organization. |
| RDP | Recreational Dive Planner |
| SI | Surface Interval |
| IAND | International Association Of Nitrox Divers |
| TDT | Total Dive Time |
| OWI | Open Water Instructor (BSAC) |
| AAS | Alternate Air Source |
| IDEA | International Diving Educators Association; Diving Instruction Organization. |
| PADI | Professional Association Of Diving Instructors |
| OW(D) | Open Water (Diver) (PADI) |