Understanding Rebreathers - Part 1

No worries, I watched PT 1 again to refresh before watching pt2.
Again, thanks for explaining simply and clearly, appreciated 👍🇬🇧

Thanks for the videos harry. Are there any reason to use both o2 control systems i.e have a leaky valve and an electronic control system. Or would it not be worth the added complexity and points of failure?

First ccr dive was 2009 AP classic, saves considerably on gas costs, helium is expensive

This is by far the best information about rebreathers I’ve seen so far. Well done!👌☀️🇸🇪

Hi Harry, what are your thoughts on Poseidon’s solid state oxygen sensors? From Poseidon’s brief description of their functionality, it seems that they sort of function the same way a pulse oximeter detects oxygen saturation in hemoglobin (I could be wrong). Do you have any experience with these?

Very well explained. Do you go to the dive shop to get your o2 tank topped up for your rebreather?

Great video. Simple, clear and very instructive

HA HA! My friend…. Thanks for this.

Brilliant! I've been teetering on the edge of closed circuit since reading a Pete Mesley article last year and you just took a lot of mystery out of the basic concept for me - Thank you Doc 🤿

Awesome work mate but crap Harry... I'm that one guy diving a KISS Sidewinder in NZ :)! I love it though and luckily it's simple enough with a lot of info online and my local AP Inspo specialist diving shop has been awesome at supporting me.

I'm really curious Sir ,did you used rebreather on that thai cave rescue? Or just regular tanks?

i`m not diver at all, but it is the case when you are watching video with interest and pleasure. thank you Sir!

Come here from seeing you on dive talk. That deep dive cave project you talked about was amazing to see. I’m going to be starting my rebreather training in a week I’m really looking forward to it.
Can I ask you what’s your view on miflex hoses on the oxygen side of the system? Everything I’ve seen about them say they are only suitable for upto 40% o2?

What happens if that single solenoid on the eCCR fails, or sticks open/closed? Is there a redundancy/bypass to turn the system into a manual CCR if need be?
Also, what happens in the event of a total power loss? Just got to bailout of the system?

Here from the dive talk. I'm not a diver but am very interested in physics, biology and technical systems. Great content!

Thanks for the overview!

Sir , are there any contraindications or precautions to be taken for someone who has Asthma and wants to join scuba diving training ? can you please suggest any books or articles related to this topic ?

This is top quality content. Thanks for sharing.
If CO2 scrubber is the limiting factor do you have a way to know during a dive how much of the absorbent is used up?

I just love your videos and respect all you have achieved in cave diving. I was happy to hear that you loved the Nerd 2, because I was on the fence before your video.

For the reason you mentioned about having a rebreather that is well supported in the area you are diving, and for ease of diving on boat, i'm leaning towards KISS Sidwinder in Mexico. Liberty Rebreather is what I would prefer.

Thanks Richard, I found this really helpful

Thanks so much, this is really helpful and nicely put

We def want to see you dive more, of ANY kind of dives and comment more on other dives.

Question can you use a ffm on a rebreather

Hey .u should come to Greece and explore the vast cave system of Vouliagmeni.its a deep labyrinth, super clear waters and huge rooms

Would be very interested in seeing a video on helmets and other gear ideas for different kinds of dives, thanks Rich

Awesomely informative video. Best general rebreather explanation I've found so far. Great job

Excellent presentation. 😃👌👌👌

This was fascinating. Thank you!

Why don’t people use the old navy cdba rebreathers ? Relatively cheap simple and reliable .

Is air integration crucial for a drive computer that's used for CCR?

Dr. Harris you are an amazing diver and anesthesiologist! Ps Ketamine is also used in the military in frontline injuries due to the pain killing and anesthesia effects it has without as many drawbacks present in morphine such as lowering of respiration/blood pressure/heart rate.

you are a natural teacher....great job

Teach me master🙇‍♂️

Your mention of Boyle's law got me thinking about the other gas properties like ideal gas law and Charle's law, and specifically the effect temperature would have on partial pressures and volume. I wonder what the benefits of heating breathing gasses to closer to body temperature (say 90F/32C) would be, and whether that could be a useful improvement in cold water/deep dives

Both in reducing the PPO2 you're inhaling, and reducing the energy your body uses to heat up gasses. With how common suit heaters have gotten, I can't imagine it's much more effort to insulate and heat the regulator hose

From the perspective of a non diver. Rebreathers seem far better than normal scuba. I wonder whats the catch, cost?

Great explanation!

what is the "up keep" costs of a rebreathers?

Are there any eccrs with a manual system installed as a backup? In cas ethe electronic fails.

Thanks for being awesome 👍🏻 really great videos

Why is it so complicated for humans to remain underwater? First person to invent human gills is going to be a billionaire! 😂

Could you incorporate pulse oximetry as an additional safety measure? I mean you're already completely encased in sensors, hoses, tanks, rubber bags, dry suit etc so a little pulse oximetry sensor would hardly be noticeable. This sensor would measure how well oxygenated your blood actually is, not just the pO2 in the breathing circuit. In this way you could adapt and optimize the pO2 in the breathing mix continously so as to always have as much O2 as is necessary and as little as possible for your blood to still remain optimally oxygenated.

it's funny that we can't breathe water, but we can breathe a hydrogen oxygen mix. can someone completely replace helium and nitrogen with hydrogen for depths between surface level and say 60 or 80 meters?

“General overview” part 1. Christ. Here we go