I wish I would have known

[darushin]

Hello

I just purchased a Hollis Prism 2 rebreather and am in the process of scheduling the training and the thought hit me. As a CCR/SCR diver, what were things you learned after training that made you say "I wished I would have thought to ask that during training" or " Boy I wished they taught that"? Also as a side question, can I do CCR trimix without have taken OC trimix? I don't plan on diving open circuit trimix but I am not sure if CCR trimix builds on OC trimix or not.

Daru

 

[denhaan]

Hi Daru, it is not required to do OC Trimix before CCR Trimix, they are 2 different disciplines and do not cross over all that well, a common misconception. CCR is by far the best platform for Trimix diving making it considerably less expensive, better management of your gas supply regardless of depth, dramatically reducing the risk of ICD and slightly reducing your Decompression obligation. However although this rarely happens, there's always a risk of your CCR failing for which you need to be prepared with enough Bailout gas.

Peter DenHaan

 

[Mr.X]

Nice seeing your post here Peter! Met you a while back at Catalina!

Cheers,

X

 

[billgraham]

Forget about diving anything at Trimix depths for a while. The best advice I can give you is to keep everything really simple until you rack up some considerable hours with it. As for specific advice, I think that the Prism has some big counterlungs and you'll have a much easier time with bouyancy if you try to keep a minimal amount of gas in the loop. Blow it out your nose if you breathe in all the way and there is still gas in the lungs. Also, keep track of small movements up and down in the water column by watching little particles move past your mask. If you keep track of micro movements and nip them in the bud, you'll avoid the "yo yo" effect that most new rebreather divers struggle with. Lastly, that ADV on the Prism is a P.O.S. and I'd get rid of it after the class. Good luck!

 

[DepthCharge]

Hi Daru, it is not required to do OC Trimix before CCR Trimix, they are 2 different disciplines and do not cross over all that well, a common misconception.

Can you expound on this? What doesn't cross-over?
Thanks,
John

 

[Wayne at DiveSeekers]

I have been diving the Prism 2 since September and the unit is working great! As with recreational diving, Gear Config is a big one for me. My Instructor was good and let me apply everything from my Tec and Sidemount background. Biggest advice, be flexible, as questions (the only stupid one, is the one you don't ask) and be open to trying things out. I too found the counter-lungs to be big, I have been testing out the smaller lungs for Hollis and they are working well, I like them a lot. I also got rid of all the straps that are on the lungs and went with a bungee system, way more comfortable. After class & several dives I have also streamlined hose lengths and switched to miflex ones. The other big thing is side-mounting the B/O, less drag/more streamlined. Shearwater computers rock! I have had no issues with my DSV but can't wait for the BOV to come. Feel free to PM me with any questions!

 

[billgraham]

I have been diving the Prism 2 since September and the unit is working great! As with recreational diving, Gear Config is a big one for me. My Instructor was good and let me apply everything from my Tec and Sidemount background. Biggest advice, be flexible, as questions (the only stupid one, is the one you don't ask) and be open to trying things out. I too found the counter-lungs to be big, I have been testing out the smaller lungs for Hollis and they are working well, I like them a lot. I also got rid of all the straps that are on the lungs and went with a bungee system, way more comfortable. After class & several dives I have also streamlined hose lengths and switched to miflex ones. The other big thing is side-mounting the B/O, less drag/more streamlined. Shearwater computers rock! I have had no issues with my DSV but can't wait for the BOV to come. Feel free to PM me with any questions!

View attachment 141828

I'd put some weight on those hoses, looks like they are obstructing your vision. I got ahold of some from the old draeger that work pretty good for me.

 

[Mr.X]

Are you at Dutch Springs? Do you have any breakdown pics? Would love to see the latest iteration of the radial scrubber basket. How much weight are you taking to counteract the buoyant force of the canister? With the STEAM Machines version it was something like 16-20 lbs??? This was quite a while ago.

Cheers,


View attachment 141828[/QUOTE]

 

[Wayne at DiveSeekers]

Yes this was Dutch. Vision is a lot better with shorter 12" hoses. I've been making small adjustments (config, small lungs, hose lengths etc) and giving feedback to Hollis. This dive I shortened up hoses & turned fittings in. Next I'm trying turning fittings out, then I'll add weights (agreed that I'll end up with them). Too many adjustments at once can effect feedback on improvements to unit. Weighting depends on undergarments. I use an SS BP vs Alum so that helps. Last Dive I had on SANTI BZ200 with 200 Heated Vest and dove with 12lbs of additional weight. I have attached Hollis Trim Weight pockets to tank cam straps and rotate them all the way to the inside of the tank and it works great. I see you are in the NE, feel free to call or PM me if you want to check out the unit in person or hop in our pool (pool at shop) with it. You can find some photos here Hollis Prism 2 Tek Rebreather

 

[DepthCharge]

Can you expound on this? What doesn't cross-over?
Thanks,
John

I guess I'll have to answer for myself. At a CONSERVATIVE estimate 98% of OC Trimix will cross over to RB. Gas laws don't change, on gassing doesn't change. Only thing that changes is a bit better deco profile.

Now if what you're saying is don't bother with OC first because you have the RB, then I would agree that it would be foolish to do OC then RB trimix.
Later,
John