Dive planning advice

[FW]

Rebreathers?

What a predicament, virgin cave, and no easy access....

Personally, I would go sidemount, and cut my penetration short to allow enough time for a survey on the way out.

[Simon Richards]

For rebreathers, I think we'd still need a 40 each as bailout in addition to a small bottle of drive gas. But they are not for us right now anyway.

I have thought of another possibility: the cenotes are about 800 feet apart, so we could plan a 500 foot dive from one of them, move the gear to the second, and plan a 500 foot dive from that in the hope of connecting up. At most we would need just a couple more small tanks for the second dive. We would get a lot of info from such a sequence, and we'd want to dive the second cenote anyway even if the first didn't go.

For a closed circuit rebreather (CCR) you need a minimum of three tanks (oxygen, diluent and a bailout). I think sidemount is best for this situation, but it depends upon your comfort level and the tank hauling.

[Arnold Mesiser]

One of the best threads I have read in awhile!! Thanks for posting the question and all the great cooperative answers.

[Jay]

I would lean to the SM 40's. If you are not in a rush then get your wife some sidemount experience and bring her along.
If you choose to dive solo or the y valves that is your decision to make.