Diving with two cylinders gives the diver more gas, greater redundancy in case of equipment failure and better balance underwater.

The purpose of the Twin Set Diver specialty course is to familiarize divers with the skills, knowledge, planning, configuration, procedures, techniques, problems, hazards and benefits of diving with twin scuba cylinders. The Twin Set Diver specialty course is intended to serve as a safe, supervised introduction to recreational diving with dual scuba cylinders. It is also a great introduction to technical diving.