Should I try a rebreather?

[BioLumiLuna]

I've seen rebreathers in my local dive shop, and was asked about them on the survey for this site, but I've never used one before, I mainly use the standard regulator system with a yoke valve. Would a rebreather make my dives last longer or could I go deeper? Would it be easier to use than a regulator? What level of certification do I need in order to use one? And would I need to know how to use one if I'm going into the Marine Biology field?
Thanks in advance!

 

[KevinNM]

It is very useful, it allows dives that are very difficult if not impossible to do on open circuit, but a lot more demanding of care and discipline than open circuit. There are numerous ways you can get yourself killed using a rebreather that basically don’t exist on open circuit.

 

[Magnus Lundstedt]

Yes and no!

Reabreathers make it possible to do dives that are just not reasonable to do in open circuit, and saves on expensive gas when doing deeper dives.

But you should get yourself a lot more experience before going closed circuit.

There are many certification organisations that do CC training, usualy on the technical side, but also the big rec organisations do CC training. Do a lot more diving, then see where your interest take you, and chose from that.

 

[JohnnyC]

A rebreather CAN make your dives last longer. A theoretical dive on an 8lb scrubber with 3L O2 will last 10 hours. In practice it doesn't, but still significantly longer. However, there are many many other considerations that may dictate the length of a dive. While CCR may enable longer dives, it won't necessarily be the best tool to extend dive times.

A rebreather doesn't allow you to go any deeper than OC, however it is significantly easier from a logistics perspective. Trimix dil is significantly less expensive than the comparative backgas. Although you will still need sufficient bailout. The benefit is that as long as you don't bail out, you get to reuse that gas for subsequent dives.

It is not easier to use than normal OC gear. It is significantly more complicated from a diving standpoint, and more complex from an equipment standpoint.

Different agencies have different prerequisites for starting rebreather training. Each rebreather requires specific training in its use, so it's not like you can just show an AOW card and grab a rebreather and go diving.

I am not a marine biologist, so I can't answer the "need" question. However, I know of a prominent marine biologist that dives a rebreather quite often, and is well known for deep rebreather dives to collect specimens.

 

[rjack321]

1) With less than 24 dives I would say no. I wouldn't look into CCRs with less than AOW, nitrox, and an intro to tech course (or GUE-fundamentals) under your belt. And 150+ dives.

2) They are not going to be useful to you at university or in marine biology, you would not be able to use one in any university sponsored events for health and safety reasons. (perhaps once you are a tenured professor you can write your own rules/dive plans, until then no)

 

[fsardone]

.... on the other end when you master them, rebreather will give you more confort (warm and moist gas), silent diving (you get closer to critters), increased enjoyment of the dives, no sense of urgency from running out of gas at depth.

Cost is all of the above, plus the economic cost of the machine and the training and the need to keep high awareness and sharp discipline since on reb complacency kills. For real.

Cheers

 

[Jeremy Williams]

Read the link below carefully. It's a pretty long read. While there is some science-diving specific material which may be of special interest to your question, there is also a TON of useful information in that document for non-science divers.

https://www.omao.noaa.gov/sites/def...rs and Scientific Diving Proceedings 2016.pdf

 

[jgttrey]

My paradigm for deciding whether to go CCR is whether you have a desire to a significant amount of the kind of diving that you really need a CCR to do -- based on the factors that JohnnyC identified above. In other words, I would work backward from a need/desire for that type of diving, rather than forward from the "the is the next cool thing to do." That's rarely a good reason.

CCRs are great and even on recreational dives I enjoy the benefits -- but that is only after having gone down the path in the first place in order to do more challenging dives. The initial investment in equipment and training is very expensive and you have to be serious about it. It's a real commitment if you want to do it properly (safely). I would not recommend getting into CCR if you are happy staying within recreational or moderate "extended range" type profiles. Or, at least, I would wait to make that sort of a decision until you have a lot more experience, including diving around/with CCR divers, so that you can assess first hand whether it would offer you benefits that would justify a lot of money and effort.

I would echo the recommendation to get some more dives and do some more OC training first. Do a rescue class. Do a sidemount class. Do an intro to tech class OC. Those would be good starts because it gives you the capacity for longer dives and teaches bottle handling skills that are helpful if end up going CCR anyway.

 

[hroark2112]

A few questions:

What is your current certification level & dive experience? How often are you planning to dive? Are you mechanically inclined?

To answer some of your questions:

Certification on a rebreather is based on the actual unit you’re going to be diving. The courses are not cheap, so you’ll want to make an educated decision on which unit you’re going to dive before spending $1500-$2000 on the course.

In order to dive a CCR you will need to either be certified on the unit you’re diving to the depth you’ll be diving, or you need to be in a course to get certified (except for try-dives, where you’re in shallow calm water with an instructor).

The one thing most people overlook with a CCR is that you have to carry enough gas to get you safely home from the absolute worst part of the dive. You’ll need solid skills on open circuit diving before going to a CCR because when something goes wrong (note I did not say if!) you’ll have to switch to open circuit and you’ll be stressed. This is not the time to learn open circuit skills, you’ve got to have the experience to deal with problems. They will happen.

Also figure in to your decision cost. From the point where I started buying my first rebreather to the point I was certified, I had spent roughly $11,000 on equipment, cylinders, computer, training, travel and related expenses. And I started out on a relatively lower price unit. To get to where I am now....don’t ask how much I’ve spent. I own several units, sets of tanks, plus the annual cost of service and replacement of O2 cells and consumables. If I sat down and figured it out, I’d probably cry.

On the plus side, I love diving my rebreathers. I dive CCR on vacations if I can and as much as I can at home. I don’t regret the decision to dive rebreathers.

Do your research first, and ask questions. Have fun!!!

 

[Superlyte27]

It is very useful, it allows dives that are very difficult if not impossible to do on open circuit, but a lot more demanding of care and discipline than open circuit. There are numerous ways you can get yourself killed using a rebreather that basically don’t exist on open circuit.

There aren't numerous ways. There's three ways.
A CCR resolves 20 issues, and introduces 3: Too much Oxygen, Too little Oxygen, Too much CO2. These three things are easily mitigated.