Travelling / Boat Diving with Rebreathers?

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Probably the biggest challenge with rebreather diving on a longer trip is getting high pressure oxygen. A lot of liveabords may have a booster pump and oxygen, but not all.

One of the benefits of a Semi-Closed Rebreathers as they just use nitrox and not pure oxygen so it’s a lot easier to mix.

Good insight. TBH I have been planning to start with a Mares Horizon SCR as a first step into rebreathers.
I haven't been convinced yet that tech diving is that appealing to me. I haven't seen a whole lot of stuff that's below 40m that I absolutely need to see, so I'm generally happy with the compromise.
The big benefits are you're basically just using nitrox, but more efficiently, and worst case you're just breathing OC on your primary gas.

I do still plan to eventually move to CCR as I'm not the hugest fan of sidemount and CCR has the added benefit of zero bubbles and always the most effective gas mix. Would still need to sling a smaller bailout bottle for soloing.

It may end up that my compromise for travel long-term is to keep the Horizon SCR for travelling and using Nitrox. Of course, there's still the issue of scrubber packing though. Only an issue on Liveaboards I guess.
 
I get the feeling that many other (at least boat-based) dive operators aren't comfortable with them.

I don't see it, having been the only ccr guy diving with an open circuit guy, or being the open circuit guy diving with the ccr guy on the boat, an hours diving is an hours diving, or being on a ccr only boat for a dive for over 20 years


Besides what you stated, I could see the only hassle a captain would have is have to wait for you for 6 hours to come back up.

I love it


My main questions are really around what operators are happy to accomodate CCR divers though. I really haven't come across too much info on this at all.

Well ring them man


Don't do it, don't even practice in a pool without someone watching you Shallow water blackout is a risk. Your loop then fills up and your unit becomes negatively buoyant, you sink and it becomes deep water drowning.

Just came back from another solo ccr dive on pure oxygen in the ocean, oh yeah I built the ccr in my laundry


The only real problem was getting sunburn!

Surely sir you jest? Sun?


A very first source of information on that topic will be the instructor with whom you will get your training, he will have plenty of places to recommend you.
I've been doing a lot of research on rebreathers lately as I've always seen it as a future step in my diving progression.

Yes davidvan would like a plan to know where he can man


I've watched all the videos I can find, including builds / pre dive check processes for many rebreathers, and am also halfway through Jill Heinerth's rebreather book.

Excellent you're heading in the right direction here, that's a bloody terrific book
 
In the case of a rEvo a couple extra scrubbers already packed, rotate through as needed. Couple extra sets of bottles, not a big deal.

I had considered this, and I've also been leaning towards rEvo. My only apprehension with rEvo so far has been lack of flood-prevention features.
I 100% want a CCR with some kind of CO2 monitoring, and rEvo's tempstick seems to be the gold standard. I forgot how the tempstick works with packing the scrubber though.. I know it has 3 prongs that protrude horizontally into the sorb, which means you have to pack around the tempstick right? I'm assuming the tempstick scrubbers aren't cheap. Or do you not have a tempstick version?

This does put me at a fair bit of recreational diving on a rebreather. Which is good for keeping in practice with it.

Yeah I'd also be happy to make that compromise while travelling. I still think the bubble-free diving and lighter, streamlined setup make it better than OC. Even if you're not getting the full benefit of extended bottom time.

Lots of great insights in your reply.. thanks!
 
In the case of a rEvo a couple extra scrubbers already packed, rotate through as needed.

Answered my own previous question about the spare scrubbers.. Found the cassettes with the rMS probes. EUR240 each (USD$293, AUD$378). The regular non-rMS cassettes are only EUR60 each, so the rMS ones are very expensive. Quite a steep price, but probably worth it to save a bunch of trouble on the liveaboards.
I guess you probably just need to carry a little extra sorb to top up in case it settles during travel.
 
Dude you really should be to start looking
flood-prevention features
mate don't flood it, and having increased my rEvos lung capacity I put a couple of extra shamwows in there
...
read all stuartvs stuff

Will do.. But I'm a bit confused. Are you saying the rEvo is dangerous because of its lack of flood-prevention/recovery features?
Or are you saying that they're not really a problem if you take steps to prevent it?
 
I had considered this, and I've also been leaning towards rEvo. My only apprehension with rEvo so far has been lack of flood-prevention features.
I 100% want a CCR with some kind of CO2 monitoring, and rEvo's tempstick seems to be the gold standard. I forgot how the tempstick works with packing the scrubber though.. I know it has 3 prongs that protrude horizontally into the sorb, which means you have to pack around the tempstick right? I'm assuming the tempstick scrubbers aren't cheap. Or do you not have a tempstick version?



Yeah I'd also be happy to make that compromise while travelling. I still think the bubble-free diving and lighter, streamlined setup make it better than OC. Even if you're not getting the full benefit of extended bottom time.

Lots of great insights in your reply.. thanks!
I think you are over thinking things. With the fairly mild dive profiles it sounds like you plan to dive, you bail out. It's that simple. Needing flood tolerance and all that other stuff is more important when you are doing deep cave dives and deep technical dives. You rarely see anyone take a rEvo into a cave. While capable of doing a 100M dive when properly setup, rEvo isn't common there either. Boat dives off the coast of California, typically up to 200' (Opps, Aussie conversion, 65M) it is common for half the boat to be filled with rEvos. Good line up of rEvos on the bench in Truk.

As for if I run RMS, no I don't. When I got my rEvo it was after a long spell of the original couple versions of the sensors that were highly failure prone. Having a discussion with my rEvo instructor we (collectively) decided that RMS was not for me. With the 2 scrubbers and the rotation program I am happy with it. If I was pushing the limits of both scrubbers in a single dive very often I might want it more. But my shorter duration diving, I really just use one scrubber and the second is the backup plan.
 
Surely sir you jest? Sun? [in Scotland]

I've never uttered these words in my life before: "I wish I'd packed the suncream for a trip to Scotland"!

Was hot and sweaty on the boat, then jumping into the 8 degree / 46F water soon changed that!

Anyway, as the only CCR on the boat and doing 'recreational' depths it was absolutely fine. However... there's a lot more "off boat" unit maintenance required, cleaning the unit, replacing scrubber, topping off gas, building the unit, etc. A good couple of hours worth.
 
Flood recovery is kind of a personal choice and something the anti-revo crowd like to beat on it about. There are several sidemount units dived aggressively in caves that are probably even worse in terms of a flood recovery and more dangerous for other reasons, but seem to have lots of enthusiasm towards them by people just stepping into ccr diving. I have a friend that wants to start on a sidewinder and that thing is very unforgiving although really cool. The revo has going for it a very simple loop that is not likely to leak in the first place compared to units where the counter lungs are not integrated into the can having more connections because of it. The biggest risk for a flood is taking dsv out or having the mouthpiece tear. You have to be really diligent checking your mouthpiece predive and I hold it in with my hand jumping from any height. Taking the dsv out underwater or on the surface is to be avoided or you need to be damn sure its closed again not really unique to the revo. I would argue you are equally screwed if you puncture a loop hose regardless of unit and many units you have more hose to worry about. My real concern with the revo in terms of water in the loop is longer working dives where I have built up a lot of condensation which becomes concerning for me after about 2.5hrs. I did my cave course on my revo and it was fine....me not so much...lol. I think if was gonna get into serious cave diving I would pick a different unit like a meg tiburon with bmcl's or other clone. Boat diving a revo is great. I think one of its advantages is it pretty simple to get kitted up to dive if you keep your configuration simple which works good on boats. Some of the other rebreathers are just inherently more complex which is fine cave diving where you have all the time in the world. If you had a third scrubber to bring along packed you could do a lot of diving in a day without any risk of a mess. I'll pop my unit open and dry it out mid day on the boat, pretty easy. I live in a terrible place so I make south florida home base for diving, most of the diving I get to do off a boat is limited to 2 hours or so rec or tech trip. I dive with oc rec divers and it works out just fine. I have my bailouts configured so I can completely hand them off to share gas. I usually dive with two for skills purposes regardless of whether its needed. If the plan on a rec trip is two dives on one site its generally not a issue to do one long dive with a buddy, make a 40m or so wreck dive into a tech dive.
 
Flood recovery is kind of a personal choice and something the anti-revo crowd like to beat on it about. There are several sidemount units dived aggressively in caves that are probably even worse in terms of a flood recovery and more dangerous for other reasons, but seem to have lots of enthusiasm towards them by people just stepping into ccr diving. I have a friend that wants to start on a sidewinder and that thing is very unforgiving although really cool. The revo has going for it a very simple loop that is not likely to leak in the first place compared to units where the counter lungs are not integrated into the can having more connections because of it. The biggest risk for a flood is taking dsv out or having the mouthpiece tear. You have to be really diligent checking your mouthpiece predive and I hold it in with my hand jumping from any height. Taking the dsv out underwater or on the surface is to be avoided or you need to be damn sure its closed again not really unique to the revo. I would argue you are equally screwed if you puncture a loop hose regardless of unit and many units you have more hose to worry about. My real concern with the revo in terms of water in the loop is longer working dives where I have built up a lot of condensation which becomes concerning for me after about 2.5hrs. I did my cave course on my revo and it was fine....me not so much...lol. I think if was gonna get into serious cave diving I would pick a different unit like a meg tiburon with bmcl's or other clone. Boat diving a revo is great. I think one of its advantages is it pretty simple to get kitted up to dive if you keep your configuration simple which works good on boats. Some of the other rebreathers are just inherently more complex which is fine cave diving where you have all the time in the world. If you had a third scrubber to bring along packed you could do a lot of diving in a day without any risk of a mess. I'll pop my unit open and dry it out mid day on the boat, pretty easy. I live in a terrible place so I make south florida home base for diving, most of the diving I get to do off a boat is limited to 2 hours or so rec or tech trip. I dive with oc rec divers and it works out just fine. I have my bailouts configured so I can completely hand them off to share gas. I usually dive with two for skills purposes regardless of whether its needed. If the plan on a rec trip is two dives on one site its generally not a issue to do one long dive with a buddy, make a 40m or so wreck dive into a tech dive.
You touched on one of the reasons I got the rEvo. There are remarkably few sealing surfaces to leak. Compared to some units, there are 2 junctions holding the loop to the rebreather. Some can run as many as 8. Maintenance (general day to day, week to week) is very easy. Take the loop off, rinse or clean, same thing for the counterlungs that are easy to access once the scrubbers are out. No special counterlung drying tools needed.

Every rebreather has faults. Nobody has invented the perfect rebreather, and they never will.

Different makes and models are better at different things. Much like a sports car and a truck are both means of transportation, how they get you places and what they can do while getting you there are very different. Horsepower is important to both, but for different reasons. Picking a rebreather should be about fining the one that works with you for your needs. You can often make them work in the wrong environment, but they are not as good as the proper unit for the environment.

One of the things a rEvo is good at is travel. The micro is sized to be a carry on item. I have had mine as a carry on, placed in the overhead bin. With tanks attached no less (empty, valves removed). Not many others can pull that off.

Something to think about. What is your dive profile going to be like? If you have enough of an issue that you flood, how much do you really need to keep diving? When you are an hour back in a cave, yes it would be nice to recover and get back on the loop. But long duration recreational dives, maybe with a light deco obligation, bailing out just works and other than jacked up buoyancy you just end the dive.
 
https://www.shearwater.com/products/peregrine/

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