Titan eCCR vs. Prism 2

[mike.chuanshi]

I've been looking at some rebreathers recently and have been evaluating the pros and cons of the Titan and the Prism 2.
I'm interested in getting a few opinions about these two rebreathers from those who are more familiar with the units.

The Basics:

• Price:
  • Both are more or less the same price
  • Training costs for each would be the same.
• Size:
  • The Titan is slightly smaller
  • They both weigh about the same.
• Electronics:
  • The Titan utilizes a Predator.
  • The Prism utilizes a Petrel.
• Battery:
  • Battery life on the Titan is significantly longer (75+ hours on the primary, 50+ hours of backup).
  • This is in pretty sharp contrast to the Prism which has a battery life of 40 hours.
• Counterlungs:
  • Titan: Back-mounted, 2.5L.
  • Prism: Shoulder-mounted, 3.5L.

Around here it seems like pilots tend to favor the Titan.
The only shop on the island that dabbles in rebreathers gives preference to them both (sales, training, repair, etc.).

 

[mathauck0814]

• Counterlungs:
• • Titan: Back-mounted, 2.5L.
  • Prism: Shoulder-mounted, 3.5L.

This is the most major difference between the two. In fact, I think you have to answer the "where do I want my counterlungs" question before you can even begin to narrow down units you're interested in. Neither of these units made my short list as there aren't many people doing the kind of dives that I'm interested on them. Just my $0.02.

 

[Dr. Lecter]

The only shop on the island that dabbles in rebreathers gives preference to them both (sales, training, repair, etc.).

Island Divers recently started offering support and MOD 1 training on the rEvo, which saved me the cost and trouble of flying to the mainland to get trained on the one I scored on RBW. On the other hand, their all-inclusive (gas, boats, full keg of sorb) price of $2500 was obscene when compared to similar classes elsewhere. But from what I know of Darren and Ocean Legends, you'll get gouged by them on training, too.

Being forced to pick among a limited number of sub-optimal choices is part of living on Hawaii, but I'd look hard at a rEvo, which is what a number of my buddies here fly. The rMS system is a huge advantage here, because the warmer water is allowing those rEvo divers with real-time scrubber monitoring to get long, long times between scrubber swaps. That means you're looking at double or triple the number of dives out of a single keg of sorb. And like everything else that has to be shipped here, HI sorb prices are very high. Some of that extra scrubber time is going to be related to doing 300' dives with long deco hangs and DPV use to reduce CO2 production, but it's still a great technology for HI's warm water and limited sorb availability.

That said, I know one guy doing 200-300' dives on BI using a Prism2 and he seems to like it. I'm sure he'll chime in.

 

[mike.chuanshi]

Island Divers recently started offering support and MOD 1 training on the rEvo, which saved me the cost and trouble of flying to the mainland to get trained on the one I scored on RBW. On the other hand, their all-inclusive (gas, boats, full keg of sorb) price of $2500 was obscene when compared to similar classes elsewhere.

I wasn't aware that Island Divers was into rebreathers; I thought Ocean Legends was the only shop that serious about them. That's definitely good news.

 

[mathauck0814]

Island Divers recently started offering support and MOD 1 training on the rEvo, which saved me the cost and trouble of flying to the mainland to get trained on the one I scored on RBW. On the other hand, their all-inclusive (gas, boats, full keg of sorb) price of $2500 was obscene when compared to similar classes elsewhere. But from what I know of Darren and Ocean Legends, you'll get gouged by them on training, too.

Being forced to pick among a limited number of sub-optimal choices is part of living on Hawaii, but I'd look hard at a rEvo, which is what a number of my buddies here fly. The rMS system is a huge advantage here, because the warmer water is allowing those rEvo divers with real-time scrubber monitoring to get long, long times between scrubber swaps. That means you're looking at double or triple the number of dives out of a single keg of sorb. And like everything else that has to be shipped here, HI sorb prices are very high. Some of that extra scrubber time is going to be related to doing 300' dives with long deco hangs and DPV use to reduce CO2 production, but it's still a great technology for HI's warm water and limited sorb availability.

That said, I know one guy doing 200-300' dives on BI using a Prism2 and he seems to like it. I'm sure he'll chime in.

rEvo is a fine unit for cold water, unless you're going to shell for the titanium frame. It would help to know what you intended to do with your rebreather/what are the dives that have you interested and what depths they are at. The rEvo is a great machine for very deep, cold water. I'm less enthusiastic about it in warm water as it's too damn negative. But that's assuming that you have weighed the pro/con and come out wanting a BMCL unit.

If you're convinced BMCL is for you, and you want to go deeper than 100m you could look at the Kiss Classic, Inspiration w/ Manta CL. If you're going to be shallower, the Kiss Spirit would be my choice (and my go-to for a warm water/travel rebreather).

The electronics are a consideration, but to my mind they're secondary.

If you're not sold on BMCL, you need to do your research and figure out what type of architecture you are looking at before you worry about individual units.

 

[denhaan]

I would not recommend any back mounted counterlung rebreather (Titan), their work of breathing is not near as good as an over the shoulder front mounted counterlung (Prism2) plus an over the shoulder counterlung is very tolerant of water ingression versus a back mounted counterlung such as the Titan or rEvo. Also the Titan is too small as you want to go deeper, past 200', regardless of what you're being told. Also have a look at the Inspiration/Evolution at Home - Silent Diving LLC or Dive Kit for Sport & Technical Divers | A P Diving.


Hope that helps, Peter

 

[mathauck0814]

I would not recommend any back mounted counterlung rebreather (Titan), their work of breathing is not near as good as an over the shoulder front mounted counterlung (Prism2) plus an over the shoulder counterlung is very tolerant of water ingression versus a back mounted counterlung such as the Titan or rEvo. Also the Titan is too small as you want to go deeper, past 200', regardless of what you're being told. Also have a look at the Inspiration/Evolution at Home - Silent Diving LLC or Dive Kit for Sport & Technical Divers | A P Diving.


Hope that helps, Peter

There's data to support that the rEvo has the lowest WOB of any commercially available unit (1.6J/L), if you choose to believe the test results. The flip side of the argument is that OTSCL configurations are cluttered and contain more moving parts, o-rings, etc which can fail.

You're not going to find "facts" on the architecture front, just opinions. Mostly held by those who advocate that their machine is the best on the planet

Start with the assumption that no rebreather is perfect, you'll likely end up owning several in your lifetime and you can only address the diving you have in front of you and go from there.

 

[Dr. Lecter]

I would not recommend any back mounted counterlung rebreather (Titan), their work of breathing is not near as good as an over the shoulder front mounted counterlung (Prism2) plus an over the shoulder counterlung is very tolerant of water ingression versus a back mounted counterlung such as the Titan or rEvo.

The WOB argument is a joke to which I won't bother responding, since mathauck nailed it already.

The water issue is a real tradeoff. Personally, I find the lower number of failure points, clean chest, and case-protected counterlungs sufficiently valuable to give up most flood recovery abilities. And unless you're brave/dumb enough to dive CCR alpinist, bailing out is always an option should you somehow manage to flood your unit. But there are surely a number potential flood scenarios where you could stay on the loop with OTSCL but would be forced to bail to OC with BMCL. Still, I refuse to give up the simplicity of a clean chest.

Personally, I would avoid any unit produced by AP. Their cell policies alone are enough to not use one of their CCRs, and recently they managed to paint their users into a corner where no cells for AP units have been available. At all. http://www.rebreatherworld.com/insp...hers/48496-ap-o2-sensor-availability-wtf.html

 

[tstormdiver]

There's data to support that the rEvo has the lowest WOB of any commercially available unit (1.6J/L), if you choose to believe the test results. The flip side of the argument is that OTSCL configurations are cluttered and contain more moving parts, o-rings, etc which can fail.

What "moving parts" are in the counterlungs? I have a Prism2 & have been thrilled with it. If you want to call them "moving parts", the only things in my counterlungs are the ADV/MDV & the manual oxygen addition.... I don't get what you're getting at... I have had my unit for nearly 2 yrs & have never had a failure of the counterlungs,.. I also know of those that have had the Prism since it came out on the market & have had no failures of the counterlungs. Realistically it has no more failure points than any other unit out there. Also what was said above about the Prism2 being much more tolerant of water intrusion. I have had a considerable amount of water in my counterlung (practicing loop floods) & was able to get rid of 90% of it & none of it got into the canister. Any way you slice & dice things, one unit may have an advantage here, at the cost of an advantage there (give & take). The trick is to find the most advantages that fit the diving you want to do.

 

[mathauck0814]

What "moving parts" are in the counterlungs? I have a Prism2 & have been thrilled with it. If you want to call them "moving parts", the only things in my counterlungs are the ADV/MDV & the manual oxygen addition.... I don't get what you're getting at... I have had my unit for nearly 2 yrs & have never had a failure of the counterlungs,.. I also know of those that have had the Prism since it came out on the market & have had no failures of the counterlungs. Realistically it has no more failure points than any other unit out there. Also what was said above about the Prism2 being much more tolerant of water intrusion. I have had a considerable amount of water in my counterlung (practicing loop floods) & was able to get rid of 90% of it & none of it got into the canister. Any way you slice & dice things, one unit may have an advantage here, at the cost of an advantage there (give & take). The trick is to find the most advantages that fit the diving you want to do.

At the very minimum, the T in the breathing loop at the OTSCL is an interface/failure point that BMCL setup does not have. Personally I don't understand why you folks get so much water in your loop that you worry about tolerance, but that's cool if it was a requirement for you. I agree that you just need to spell out your priorities and find a machine that best matches them (understanding that it's likely no machine will tick all the boxes)