Lightweight rebreather for a recreational diver

[lemon]

I certainly see the value of CCRs below about 250fsw, also for very remote places like Truk where helium is available in teaspoon quantities. Plenty of people are taking outstanding pics and video on OC though so while bubbleless might help that it can't make up for genuine photographic skill. So shallower and recreationally, I concur, their value is dubious.

well, thats an opinion and you're certainly welcome to yours. i hesitate to re-open the oft repeated debate about who should or should not dive rebreathers. different strokes for different folks.

the reason why i started diving CCR was for cocos where the hammers are so skittish of bubbles. certainly photographers need photographic skill but going bubbleless is an entirely unique way to interact with marine life and there is just no comparison when it comes to certain species. i still dive OC although i now find bubbles to be deafeningly loud. just returned from an amazing week with oceanic white tips in the bahamas. certainly no need for a rebreather with THOSE sharks....

 

[lemon]

2. A 70'/180 minute dive on rebreather is a NDL dive whereas OC using 40% Nitrox and 100% O2 for deco is a deco dive (for a few minutes) requiring more than 440CF 40% nitrox. NDL and gas requirements are greatly reduced on a CCR even within recreational depth limits.

exactly. in fact, an air diluent CCR gives you the GREATEST ndl advantage within recreational limits.

 

[rjack321]

2. A 70'/180 minute dive on CCR is a NDL dive whereas OC using 40% Nitrox and 100% O2 for deco is a deco dive (for a few minutes) requiring more than 440CF 40% nitrox. NDL time is greatly extended and gas requirements are greatly reduced on a CCR even within recreational depth limits.

I don't get it. None of our sites have that much to see that 3hrs of BT would be "fun" or even remotely warm even with CCR. And no local boat would let you do 3hrs either, and slack is never that long. So really saying a 70fsw OC dive is "limited" by gas or deco is missing all the other variables which come into play.

In a cave sure, there are 3hr cave dives but that's not a recreational OW dive and the bailout (as you probably can guess) is huge.

 

[TSandM]

You know, some of the dives I did in the Red Sea could easily have been three delightful hours. The water was warm, and I was in a dry suit. Nothing was tidal. We had no current to speak of. And the structure we were on was beautiful from 150 feet to the surface (and maybe deeper -- I don't know, because we didn't go there). I could easily see someone wanting a three hour dive, instead of two ninety minute ones.

I don't want to do dives that long in Puget Sound. But I'd certainly consider them in the Red Sea, if it weren't for the annoyance of trying to bring that much gas with me.

 

[Mr.X]

Seriously, when was the last time a newb wanted to do a three-hour dive? Some things that come to mind are hydration, exhaustion for such a long period of time etc. Snorkeling is a different story all together because you're basically putting around.

Back in the day I used to tell NE boat captains that I would be underwater a good 90 + minutes. I'd give them a detail of what I would be doing + a plan. That said - they were always nervous about spot-on run times and on more than one occasion I had a mate from the boat splash in and do a anchor check. Not seeing any bubbles, or deco indicator worries a lot of captains. My favorite check-in mate was Joe Coccoza from Pod Diver Radio who checked in on one of my longer dives - after seeing enough of us on CCR he moved over to the Yellow Box.

X

 

[Dive-aholic]

In a cave sure, there are 3hr cave dives but that's not a recreational OW dive and the bailout (as you probably can guess) is huge.

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.

 

[DwayneJ]

I don't get it. None of our sites have that much to see that 3hrs of BT would be "fun" or even remotely warm even with CCR.

Two buddies and I have our own boats and we have a bunch of coastline to play with. There are some rebreather friendly charter boats who stay on station at a large wreck for two OC/one CCR dive as well as CCR only charters who accommodate longer dives. I stay warm at depth but one of the most valuable benefits of a CCR is a warm moist loop so you are not breathing cold compressed air - this helps tremendously to keep your core warm.

I do know a OC/CCR diver who uses a heated vest - Silent Planet

 

[down4fun]

I don't get it. None of our sites have that much to see that 3hrs of BT would be "fun" or even remotely warm even with CCR. And no local boat would let you do 3hrs either, and slack is never that long.

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

 

[SFLDiver3445]

I don't get it. None of our sites have that much to see that 3hrs of BT would be "fun" or even remotely warm even with CCR. And no local boat would let you do 3hrs either, and slack is never that long. So really saying a 70fsw OC dive is "limited" by gas or deco is missing all the other variables which come into play.

We have a site here off Ft. Lauderdale, Florida that is in approximately 70 feet of water. On this site sit three wrecks, lined-up stern to bow, and seperated by a distance of less than 100 yards between each wreck. These wrecks have been down for quite some time, so there is a fair amount of growth and marine life on them, and they make for GREAT site for underwater photography!!!

We often go out on a charter boat and dive these wrecks as one long dive. For those of us on rebreathers, the captain will drop us on the first wreck, and pick us up on the last wreck 3 hours later, almost always with less than a couple of minutes of required decompression. When there are open circuit divers onboard, they will hit the water on the first wreck with us, surface after their first dive, then hit the water again for the second dive after the captain repositions the boat on the last wreck.

This system works out great, because the open circuit divers get two dives, and the rebreather divers get one long 3 hour dive - It's one of our favorite dives in this area!

 

[SFLDiver3445]

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

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