Rebreather Purchase question

[Chuck_Northrup]

Jon,

It is generally agreed upon in the rebreather community that the "perfect rebreather" has not been invented yet. You need to look at each unit as a specific tool for a specific dive. Unfortunately what one person sees as a benefit another will likely see as a disadvantage so there never will be a "perfect rebreather" for everyone.

Rather than wait along for this enigmatic technology to develop some ambitious RB divers have taken it upon themselves to create their own rebreathers (modifications and homebuilt systems). It is not something as an instructor that I would encourage or endorse, but a lot of people have done it. Just check out and go into the modified (special) or homebuild sections.

The main reason it happens so frequently is that the process is not overly complicated and some people have an inherent need to mess with things : I believe you are certified for the Dolphin and should have a basic understanding so I will use it as an example.

#1. Block the sonic flow orifice so that you will have diluent introduced to the system through the automatic diluent valve only (ADV)

#2. Add a bottle of O2 with appropriate 1st stage and a metering device to deliver O2 just below your metabolic rate. You will need a manual override for O2 to maintain quasi-constant PO2 (it would work on a decaying PO2)

#3. Add a 3 sensor PO2 monitoring device because you are now diving CCR and 1 sensor is no longer acceptable.

This is basically an extrapolation of Gordon Smith's KISS rebreather concept. You can find out more information at
There are as many different ways to modify a rebreather as there are people willing to chop them out. If some of the information above is a little vague I apologize but I want to stay non-specific so that people do not think I am in favor of these practices Hope this info helps.

Chuck