Question Trying to decide on a rebreather unit

[Rayk]

I think I've made my decision, I will work on getting Advanced Nitrox and Deco Procedures on Open Circuit while I continue to shop around and find try dives for the P2 and Choptima to make sure I actually like the units.

If you made your mind to follow this path, which is most logical option in my opinion, i highly recommend getting helitrox card along with AN/DP. This will allow you starting your CCR journey with mixed gas decompression level where rebreathers really comes handy.

 

[Dann-Oh]

If you made your mind to follow this path, which is most logical option in my opinion, i highly recommend getting helitrox card along with AN/DP. This will allow you starting your CCR journey with mixed gas decompression level where rebreathers really comes handy.

I was told that the path should be AN/DP --> CCR --> Helitrox. The reason being that when jumping into CCR you are limited to no deco and 100ft. But with AN/DP --> CCR you are able to go to 130ft with limited deco. So basically Id be back at my recreational limits while learning to dive the CCR and then building hours and skills before jumping into Helitrox and mixed gasses.

Its also possible that I misunderstood the conversation.

 

[Wibble]

I think I've made my decision, I will work on getting Advanced Nitrox and Deco Procedures on Open Circuit while I continue to shop around and find try dives for the P2 and Choptima to make sure I actually like the units.

The ANDP (Advanced Nitrox & Decompression Procedures) will be useful as the deco procedures are basically everything you need for bailout. Specifically, manipulating stages, the NoTox protocol, cleaning up stages, etc.

The theory also applies to the nitrox mixing machine on your back (or front, or sides). If that's fresh, your MOD1 will be easier.

I don't fully understand what the benefits of the P2 are over the Choptima. From what I can tell the P2 is about double the price ($15K for the P2 vs $7k for the Choptima). Both units can get me safely to where I want to go why would I spend 2x the money of the P2. Id rather use the extra funds for actually diving.

Don't discount the other mainstream backmount units: Revo, JJ, Meg, etc. It really is useful to dive a unit that others use. These may be cheaper than the Prism 2: the Euro's dropped

One key thing to consider is if you can find someone else who's about to do the OC to CCR move. Frequently diving with a buddy where you can both practice your skills together is invaluable.

Skills include:

• Time at 6m/20ft to get stable, especially next to a platform. This is one of the hardest skills to do on a rebreather and will be frustrating at first. If you're intending to do MOD2 depths (70m/230ft) then you must master this.
• The flushes: diluent flush, oxygen flush
• Bailing out. Do. This. On. Every. Dive. More than once in the beginning. Do full bailouts occasionally, especially when you're looking at updating your skills (e.g. MOD1 air --> MOD1 helitrox --> MOD2)
• Manual running of the unit (e.g. change the setpoint to low, keep the PPO2 up at the higher setpoint)
• Ascents -- they're very very busy on a rebreather
• Use a deco bailout cylinder from early on, e.g. dive with two bailouts.
• Practice the failures: cells, lost O2, lost diluent, lost wing, lost drysuit inflate, lost computers...

Basically it's the hours and the ascents that make you better. Lots of hours at 6m/20ft will be your target.

 

[justinthedeeps]

Regular 'tech' to 40 or 45 metres, then crossover to NDL or Mod1 CCR eliminates the need for any open circuit trimix courses.

If anyone still teaching courses on air to 55 metres, recommend not doing that, ppN₂ of 5+ atm is totally survivable but feels kinda gross. Though some people are into that

[Everyone who did full OC trimix already, you are a super O.G. badass, your thousands were well spent, and will always be a better safer cooler diver etc than everyone who didn't do that ]

 

[Alekseolsen]

I was told that the path should be AN/DP --> CCR --> Helitrox. The reason being that when jumping into CCR you are limited to no deco and 100ft. But with AN/DP --> CCR you are able to go to 130ft with limited deco. So basically Id be back at my recreational limits while learning to dive the CCR and then building hours and skills before jumping into Helitrox and mixed gasses.

Its also possible that I misunderstood the conversation.

I did the "Rec trimix MOD1" and would be super annoyed if I didn't. At least to me, getting a new course in to unlock MOD2 depths may take time to organise (to be able to have the tine off), and beeing "locked" on air until then would be annoying. Even with the Rec trimix ticket there's nothing forcing you to go deeper than 30 meters.

 

[BoltSnap]

My airline of choice gives me a luggage allowance of 3x 32kg

Which one is that and what class do you travel?

 

[RedSeaDiver2]

Which one is that and what class do you travel?

Emirates airline in economy with a Qantas Gold frequent flyer card

 

[sea_ledford]

I'm one of those P2 divers that gets them for a discount. It's not really a discount as much as dealer pricing since the aquarium buys several of them at a time. We are up to 5 at this point. Cal Academy probably has like 10 of them. We are using them for coral restoration work down to 200 feet currently, but will be at 100M soonish. The Cal Academy deep team is over 500' at this point on mostly stock Prisms, including the Hollis BOV. Only change is swapping the steel 3L tanks out for 30cuft and running them valves up, and changing hose lengths as appropriate for that.

The unit dives great, and is certainly capable of doing any dive that most people will ever do. It is wide though, I wouldn't pick it for cave diving. I'm not a fan of packing the scrubber, since the only flexibility on volume is two thin sponges that get compressed to paper by the time service rolls around for replacement. Building and breaking down is fairly complicated. Of the 4.5 units I've dove (Inspiration, SF2 back mount, SF2 side mount, and LAR V) it is by far the most difficult. I am diving the front mounted counterlungs, the back mounted lungs may solve some of my gripes, but I haven't had a chance to try them out.

I'm not sure where you are getting the 12K vs 7K for a choptima, but make sure you are comparing apples to apples. $12K for a P2 must include every single option including a nerd (which I strongly recommend!). 7K for the chop is probably a fully kitted CCR with none of the OC parts you need to run it. So don't forget to add in the bpw, tank(s) regs, etc in that price. I would also not buy a new P2, as stated above you can come across used ones fin the 4K range.

Service is what would concern me most with the P2. I have heard horror stories about difficulties with service. We self service so haven't had that issue yet. But then last time I sent my SF2 in for its annual service, it took 6 months to get back.

Good luck picking! Lots of options out there.

 

[Dann-Oh]

I'm one of those P2 divers that gets them for a discount. It's not really a discount as much as dealer pricing since the aquarium buys several of them at a time. We are up to 5 at this point. Cal Academy probably has like 10 of them. We are using them for coral restoration work down to 200 feet currently, but will be at 100M soonish. The Cal Academy deep team is over 500' at this point on mostly stock Prisms, including the Hollis BOV. Only change is swapping the steel 3L tanks out for 30cuft and running them valves up, and changing hose lengths as appropriate for that.

The unit dives great, and is certainly capable of doing any dive that most people will ever do. It is wide though, I wouldn't pick it for cave diving. I'm not a fan of packing the scrubber, since the only flexibility on volume is two thin sponges that get compressed to paper by the time service rolls around for replacement. Building and breaking down is fairly complicated. Of the 4.5 units I've dove (Inspiration, SF2 back mount, SF2 side mount, and LAR V) it is by far the most difficult. I am diving the front mounted counterlungs, the back mounted lungs may solve some of my gripes, but I haven't had a chance to try them out.

I'm not sure where you are getting the 12K vs 7K for a choptima, but make sure you are comparing apples to apples. $12K for a P2 must include every single option including a nerd (which I strongly recommend!). 7K for the chop is probably a fully kitted CCR with none of the OC parts you need to run it. So don't forget to add in the bpw, tank(s) regs, etc in that price. I would also not buy a new P2, as stated above you can come across used ones fin the 4K range.

Service is what would concern me most with the P2. I have heard horror stories about difficulties with service. We self service so haven't had that issue yet. But then last time I sent my SF2 in for its annual service, it took 6 months to get back.

Good luck picking! Lots of options out there.

I was able to spend a little bit of time with the P2 instructor I know. He is saying that the "basic/stock" configuration for the P2 is about $9,400. So this will be pretty similar to the pricing on the Choptima.

 

[wayne miller]

I really fancy a Triton chestmount unit for travelling and use in warm, clear, pretty waters. This can be configured with a normal ali80 with a wing+backplate+harness and a standard set of regs (that's longhose+necklace ) with the chestmount rebreather clipped to your front. This would mean that you are a "standard" recreational diver with a lump on the front.


The chestmount boxes are half the weight -- or less! -- of a backmount unit. Much of the reason for this is there's no backplate, wing, buoyancy control. Also diluent is taken from your bailout (AKA "Dilout") so there's no separate diluent cylinder. The oxygen cylinder's also very small (1 or 1.5 litres) as it's frequently mounted transverse on the bottom of the chestmount unit.

(We had a discussion about CCR ready-to-dive weights a while back)

Weight of rebreathers -- Ready to dive?

Am curious about the weight of rebreathers in a ready to dive state. This means it's fully packed with oxygen & diluent cylinders plus scrubber, any additional weight, full harness, spare light, cutting devices, batteries, drysuit inflate... Everything except for bailout. If it's a...

scubaboard.com

My take... I have a Triton and a ISC Meg15. I trust my Meg and I do not trust my Trtion. I love dealing with the guys at ISC, I hate dealing with the arrogance of M3S even after telling them about several major issues including a major manufacturing defect that prevented me from diving after dragging that skinny little lunch sack all the way over to Asia. You pick your poison One thing I am learning is that no one CCR is perfect.. but I am continuing the search