Rebreathers
Scuba comes in three flavors, open-circuit, semi-closed, and closed-circuit. Open circuit is the most common, consisting of a cylinder and
demand valve regulator which wastes all of the gas exhaled on each breath. Semi-closed, on the other hand, implies that most of the gas is
reused and only a small amount is exhausted to the surroundings. This allows the use of Nitrox mixtures
for the system. Closed-circuit systems are usually one of two types, pure oxygen for shallow depths or complex mixed gas systems requiring gas
monitors and computers for decompression tracking. This creates a very complex system.
The semi-closed circuit rebreather (SCR) can be manufactured without the use of batteries or electronic components in a very reliable system.
It's only moving parts are the check valves in the mouthpiece and the demand valve override for deep inhalations. It can be simple, useful,
and provide many of the benefits divers seek in rebreathers. With the use of Nitrox mixtures, the benefits
of EAN use are retained with the added benefits of a properly designed SCR which includes:
- Quiet, reduced bubble operation
- Extended bottom time (due to efficient use of gas)
- Lighter, more comfortable diving systems
- All the physiological benefits of EAN (Nitrox)
Other advantages of the semi-closed circuit rebreather become obvious with use in each dives chosen environment. For example, the inspired air is moist, not-dry, helping to eliminate "cotton-mouth." Also, the gas is warmer, reducing heat loss in cold-water diving. Buoyancy needs only be set once at depth. As the diver breathes, the system acts opposite to the lungs producing no change in buoyancy from inhalation to exhalation. This takes some getting used to for experienced divers.
All of the oxygen considerations for Nitrox continue with the SCR as well as planning for nitrogen no-decompression conditions.
So, are you ready to take the course? The course fees break down as follows:
- Nitrox & Rebreather
- Cost: $495
- Includes:
- Nitrox and Rebreather Textbooks
- 4 Dives
- Classroom and Pool Sessions
- Use of Rebreather and Accessories
- Rebreather Only
- Cost: $395
- Nitrox is a prerequisite
- Includes:
- Rebreather Textbook
- 4 Dives
- Classroom and Pool Sessions
- Use of Rebreather and Accessories