| Acronym | Meaning |
| PPB | Peak Performance Bouyancy |
| SAA | Sub-Aqua Association |
| RIB | Rigid-Hulled Inflatable Boat |
| PDIC | Professional Diving Instructors Corporation International; Diving Instruction Organization. |
| ITW | Instructor Training Workshop (BSAC) |
| SPG | Submerssible Pressure Guage |
| RYA | Royal Yachting Association |
| SI | Surface Interval |
| RSTC | Recreational Scuba Training Council. Organization That Sets Basic Guidelines For Scuba Diving Agencies. |
| RNT | Residual Nitrogen Time |