There are many aspects in which
the CCR rebreather differs from the SC rebreather. Please check
this page to see the differences. The most important difference
is that the CCR maintains a fixed pO2 while the SCR has a changing
pO2. The CCR keeps the pO2 fixed and will mix oxygen with diluent to
have the ideal mix at each depth. Please note that the composition
of the gas changes with the depth while maintaining a fixed pO2!
This will make it possible to make long and deep dives using very
little gas. Downside is that the CCR is a much more complicated
piece op equipment that asks for great care and maintenance in using
such unit. Also the price is at least double when compared tot the
SCR. Although each year many new CCR divers are trained is still is
a rather small group using these rebreathers. (10000-15000 users
world wide! (2006).
When the CCR rebreather is used
with a Trimix for diluent you are able to dive the unit to depth
beyond 150 meters! This asks for a great experience and training.
Only a very little number of people dived the ccr to these depth.