Hey Mike.
Glad you are interested in the dark side of diving, I suggest that you have a few conversations with local divers whom have been diving rebreathers. There a quite a few in the Long Island area. Several members of the LIDA group have been on rebreathers. You will have to excuse me, my memory for particular names is not the greatest. I have been diving with the Sea Turtle out of Montauk, the last few years, and the captain (Chuck Wade) and both his mates have been on rebreathers for a few years (Meg, Kiss, Inspiration, Optima, Hammerhead) are the units they have been or are using.
I started with a Sport Kiss and I am now using a Meg. To help you make a choice please speak to divers whom have been using the units, you can then make a decision as to which unit suits your particular needs.
This may sound like and add, but come and do a few dives with us on the Sea Turtle
Sea Turtle; Charters.com,wreckdiving,sharkcage,montauk,blockis land,longisland we will be glad to answer any and all your queries about these units.
Gabe
