Lightweight rebreather for a recreational diver

[rjack321]

Why do so many people think this?? I bought a GEM specifically for diving in JB. I've been doing 2 stage dives to get 2-2.5 hour long dives in there. The GEM will allow me to do those same dives with just my sidemount cylinders. Just because I'm in a cave doing a 3 hour long dive doesn't mean I'm 1.5 hours from the entrance. I've swam out, while pushing a scooter, from 2500' breathing an AL80 and had plenty of gas left over when I got to my deco cylinder. I can easily swim out from 4000' on one cave-filled LP85 and have gas left over. Plumb the GEM into one cylinder and use the other as bailout. That's all that's needed. You only need enough bailout to get out of the cave from your farthest penetration, which you need when diving OC anyway. So, cut out the gas you need to get in and do the dive and that significantly cuts down the number of cylinders you need to take into the cave with you. Not every dive into a cave is a linear penetration.

I think if you budget for a CO2 hit, take away the flow helping you, your bailout needs are gonna go up... Besides I actually agree with you, CCR or something like the GEM can be good ways to replace 2+ stage dives when you don't have an army along. Recreationally for places like the NW, PNW and Cali where the OP is, I don't see CCRs are all that useful. These dives are going to be limited by some other factor than gas most of the time. At least they are for me, we do 70+mins on 32% and run out of steam, and off my own boat so I don't even have to deal with a skipper's or other passenger's blessing to stay on one site all day.

Location is key. Once again we are spoiled here in Florida as we have several operators that will take us out to a site of 4-5 wrecks in a trail and drop us for three hours. We explore, penetrate, photograph one wreck and swim to the next, and the next, etc. If the boat is a mix of o/c and ccr they will drop everyone on the first wreck, the o/c's go up do there surface interval and meet us on the their second drop to the last wreck. It's warm enough to do in a 3mm in the summer

You and DwayneJ and obviously spoiled brats

 

[rjack321]

Kim, my post is referencing the same dive as yours - you beat me to it!

a trifecta of spoiled rottens!

 

[Dive-aholic]

I think if you budget for a CO2 hit, take away the flow helping you, your bailout needs are gonna go up... Besides I actually agree with you, CCR or something like the GEM can be good ways to replace 2+ stage dives when you don't have an army along. Recreationally for places like the NW, PNW and Cali where the OP is, I don't see CCRs are all that useful. These dives are going to be limited by some other factor than gas most of the time. At least they are for me, we do 70+mins on 32% and run out of steam, and off my own boat so I don't even have to deal with a skipper's or other passenger's blessing to stay on one site all day.

Even with a CO2 hit and no flow, I can still eliminate my stages. Like I said, I have swum out from 2500' in Jackson Blue when the flow was minimal and had over 1000 psi left in my AL80. Based on that, I can get out from about 3500' on an AL80. A cave-filled LP 85 is 150% the gas in an AL80, plus the one I'm plumbed into with the GEM also has gas available..

I do agree with the limited usefulness in your area. I'd be cold long before I ever hit turn pressure!

 

[rjack321]

I do agree with the limited usefulness in your area. I'd be cold long before I ever hit turn pressure!

The guys doing 240fsw+ need them. We have some wrecks at 270-300fsw and while that <can> be done on OC here, they are bascially the playground for the CCR guys. We don't have hammerheads etc. I see comparable (shallow) photography from OC and CCR folks so its not some magic tool to take stellar pics.

 

[Dr. Doug Ebersole]

The appeal of the GEM to my wife has nothing to do with 3 hour dives. She like the idea of easily doing a two tank recreational boat dive trip on an AL 50 or AL63, depending on the depth, and never having to change tanks. There are multiple ways to use this new rebreather.