Rebreathers have been around longer than Scuba. They were originally used for mine rescue and then for submarine escapes. The Italian Frogmen during WW 2 captured the public imagination with their daring, riding two-man torpedos and using rebreathers.
After WW 2, the rebreather became commercially available to the public. Now there are many brands competing for a growing recreational market. The big decision for a diver is what type of rebreather best suits their needs. There are a number of different types of Rebreather: Oxygen, semi-closed and closed curcuit.
Oxygen rebreathers have a specialist application and limited depth of operation. This makes them generally unsuitable for recreational divers.
Semi-closed rebreathers (SCR) use nitrox supplied to the diver in controlled dosage. These are more simple to operate and are mostly designed to operate in the recreational depth limits. The SCR increases the divers bottom time. The KISS GEM is one of these.
Closed-circuit rebreathers (CCR) are the most capable and are used at both recreational depths and beyond. The CCR is the ultimate nitrox mixing machine and can be used with trimix to achieve underwater durations only dreamed of by Technical Scuba divers. CCRs are generally classed as eCCR or mCCR. eCCRs have a solenoid that controls the amount of gas injected into the loop. With mCCRs, the diver decides when and how much gas should be injected into the loop.
The KISS GEM is a SCR. The KISS Orca, Classic and Explorer are mCCRs. We sell and train divers to use all the KISS rebreathers.