purchased a Hollis P2 and am currently getting trained on it. Can't wait to get it wet. I was going to buy one a few years ago, this guy who owns a scuba shop in Waikiki told me how dangerous they are so it kinda scared me. When the pandemic started I found Dive Talk and was back to thinking it might be for me. I live in California and dive Hawaii, California, Mexico, Jamaica, Florida, etc... Never been to Africa or Europe but want to go. I'll be in Cozumel in the fall. Anyways, I like to leave comments to help the algorithm. Thanks for your video, love to see scuba content on youtube. Like the info on crossover, that was a question I had for my instructor, just hadn't asked him yet.
No worries William. If you have any more questions on CCR you want to ask, feel free. I'm more of a mechanical CCR fan and will be looking to trimix dive the USS Oriskany in August... So I'm a massive fan too
All the required info, in a concise and clear video, and for a change, without any technical mumbo jumbo, to scare the newbie away :) And let's being frank : I'm a geek and a tek diver ! :D
Thanks JM. I have to admit, I was impressed with Jon's 'Lets build a rebreather' idea and thought it really worked. I've learned so much from working alongside him...
Nobody ever mentions that it's more difficult to breathe on a rebreather. Yes, one gets used to it and one adapts, but it is more difficult to breathe on than on open circuit. One has to, depending on rebreather and position of counter lungs, make more of an effort in comparison to open circuit.
Hey Bombous Boy. There are a lot of 'but if's' I could come back with, but fundamentally you're probably right. A lot of work has been done in recent years to make over-balanced open circuit regulators where the intermediate pressure in the breathing hose is 10+bar over-ambient. On a CCR loop pressure is at ambient pressure - so if you're at a consistent depth and consistent orientation, CCR breathing is like breathing normally. If you roll over or descend.... then yes I does get more challenging and can be a surprise to new CCR divers. How it effects you depend on what OC set up you dive with and what CCR you use too. My favoured CCR is the KISS Spirit, which has wrap around counter lungs specifically to try to eliminate the effect on WOB of front or back mounted counterlungs. Excellent comment, and thank you for taking the time to watch and feedback
Whoa, that's rad! The rd1 oxygen rebreather seems like a sweet choice for affordable rebreather diving. Keep us posted on the conversion to mccr, it's gonna be epic!
I have always been afraid of CCR and at the same time attracted. Without naming and shaming particular manufacturers would you say that diving accidents are due to diver error or is there an engineering problem, where the problem being that the system does not fail safe and what is being done to address these things. Wonderful technology but some of the fatalities scared me and I cannot work out whether this is because people are blase coming from open circuit? I would welcome your comments on safety diving with a rebreather.
I'm sure that there must be some stats out there somewhere, but I'll base my response on my own experience and the experience of people I know who dive CCR. CCR's, like any other scuba equipment, can fail. Like most other scuba equipment, the fail very rarely if they are well maintained and looked after. From my own experience, most of the issues (which could result in an incident) have come about from user error. Either by not following set up and testing checklists or not monitoring your system when on a dive. When you're learning CCR you learn all about the self rescue and bail out drills, and its important that these are practiced to develop good muscle memory too. There is also a correlation between CCR divers and diving accidents where the divers are pushing limits (technical diving). The CCR does allow you to have significantly longer or deeper dives, but all of the normal rules of deeper diving still apply. Incidents happen when people push the limits, don't follow their plan and do not fulfill their obligations under water too - whether CCR or OC. My over riding experience though - user error is likely to be the biggest causal factor though. Probably by a large margin.
@@DeeferDivingCarriacou Thanks for your reply. I know certain things have been improved so if you jump in with AP Valves without doing checks- it will operate (assuming tanks valves are open! I think given human factor sounds like we need to idiot proof more, because humans are fallible and everyone can have a bad day. Being experienced its too easy to become complacent (speaking as an open circuit diver with no CCR experience or training- apart from watching your videos! 😁😜
How to make with vomit? There are times where I have vomits during diving (e.g. at 20mts deep); and with open circuit regulators is easy to maintan it in mouth... how difficult is to vomit with CCR? how do you do in case of vomiting ?
That is a good question.... When you vomit, do you do this through the reg or do you take your reg out? On a CCR you would need to close the loop first. If you're diving with a DSV, you'd remove the mouthpiece and either chunder into the water or put in your reg from your bailout and vomit. If you're using a BOV, you could just switch to open circuit and chunder away. Switching back onto the loop when you're done. You will still get a residual taste of it every few breaths though..... Do you tend to vomit because of your gag relfex? if so you might want to consider switching to moulded mouthpieces...
Does CCR require another person with CCR to make a pair? or it is OK to dive with someone w/open circuit? How often do you see pair of CCR & open circuit divers?
You get the full bubble free experience from diving with another CCR diver.... but you can dive with OC guys too. I tend to dive with a couple of guys who will come out with me with a couple of sidemount tanks - they'll put a nitrox mix in there and keep me company. The important thing is that you teach them how to recover you in the event something goes wrong... On the island where I am, I am the only instructor teaching CCR and we are the only dive operation offering CCR, so if you're going to see a CCR diver you'll be with me. That said, I will #have to dive on CCR every now and then, and will jump in the water with an OC buddy...
What I need to know and can not find is how long can I stay at 40 feet on one dive. I use two 100s and can stay one and a half hours tops. I work hard and breathe hard. Will a rebreather allow me 6 hours at 40 feet without coming up?
It depends on a couple of factors, but theoretically the answer is yes. Those factors include what temperature the water is that you're diving in, how big is your O2 cylinder and most importantly, what is your scrubber capacity. You're still going to consume and metabolize O2, and you need to have sufficient O2 with you to last the dive. We typically don't use too much, but for a 6 hour dive you'd probably need something like a 5L tank (I don't know what that is in CUFT). As we exhale CO2, we need to be able to scrub that from the breathing loop and we use a special soda-lime based powder to do this. The scrubber works by creating a thermic reaction which binds the CO2 to the scrubber. The scrubber does not work as well when its cold, and typically does not last as long when diving in cold water. NDL is usually the limiting factor, and whilst we might be able to dive with 40% nitrox in an OC setup, on a CCR we could be diving with the equivalent of 60% nitrox (or higher if we were shallower - I'm using these numbers for illustrative purposes). This would vastly increase the NDL. But aside from that, with the proper training in decompression procedures.... NDL's become something we nod at as they go by. So in summary, regardless of breathing performance, a CCR will provide you with the facility to dive significantly longer than with a doubles/SM configuration at 40ft, but there would need to be some considerations to the rig you're diving. In this regard, not all CCR's would facilitate a 6 hour dive. Of course, I'd have to ask.... why the hell would you want a 6 hour dive? LOL
@@DeeferDivingCarriacou Thank you for your information. I have been diving in fast (3mph) rivers for 28 years. I am an underwater fossil hunter. I use twin 100s and get between 1 hour and 15 to 30 minutes time at 35 feet. I work hard and breath hard. I wear 60 pounds of weights and dive 4 dives a day 5 days a week. My mother got ill and Intuit to take care of her. She has passed away and I want to get back to work. I am 71 and want something lighter than double 100s. I want to stay down 6 hours a day. I will start with 149 Steel Tanks and then get a back rebreather. Your information is very needed.
You're right. High CO2 is the trigger to want to breathe and as it builds up more and more your desire to breathe builds up too. Which is why CCR's can be so difficult. If you scrub out the CO2 and don't provide enough O2, you can start to experience all sorts of hypoxic issues, including lightheadedness and loss of consciousness. Thats why its important to always fully test your CCR before getting in the water
