Do all rebreathers require a bailout bottle on board ?

[formernuke]

Ok so questions about the poseiden. After looking at there site

Is it a eccr, mccr or hccr?
What size tanks for diluent and O2 does it use?

Looking at it, it seems to use the 2l or 3l tanks in which case a separate BO bottle should definitely be used.

 

[Wibble]

As a non-Poseidon CCR diver, am curious as to the cost of changing a Poseidon from "Rec" to "Tec". Also what is the benefit of buying a "rec" rather than a "Tec" and diving it recreationally, i.e. responsibly. Just because it can dive to 150m/500ft doesn’t mean you should.

 

[ND5342]

Ok so questions about the poseiden. After looking at there site

Is it a eccr, mccr or hccr?
What size tanks for diluent and O2 does it use?

Looking at it, it seems to use the 2l or 3l tanks in which case a separate BO bottle should definitely be used.

It is definitely ECCR however with the M28 computer it could be modified to an hccr like most ECCRs.

It is normally sold with 3 liter steels or AL 19's. The AL19's help stand the unit up which is nice. Buoyancy is about the same jst a little less gas but you really do not need the full steel's amount of O2.

Like I said in the PADI Rebreather Rec to 60 FSW course you are not required or taught to use an offboard bailout. If you are mindful of your dil and diving your unit properly you really do not use a whole lot of dil anyway. If you are using a wetsuit then you will use even less and the unit is not hard to swim up anyway. It's a light unit with a great weight to buoyancy ratio.

 

[ND5342]

As a non-Poseidon CCR diver, am curious as to the cost of changing a Poseidon from "Rec" to "Tec". Also what is the benefit of buying a "rec" rather than a "Tec" and diving it recreationally, i.e. responsibly. Just because it can dive to 150m/500ft doesn’t mean you should.

Not everyone has a desire to dive deep or long first of all. I totally enjoy silent diving for the marine life encounters and the serentity of bubble free diving.

Now I do agree that a Posiedon is an expensive piece of kit to dive shallower than 60 FSW (that is what my O2 rebreather is for) but I do not think that for someone looking to dive no deeper than the normoxic range it can be a nice unit for that purpose. Especially for what they can be found on the used market.

Few of us really needs a rebreaather and even fewer of us to be making deep long dives. It's all a hobby for most of us. Some people spend more on their hobbies than others.

Changing it to a TEC unit is difficult to say as there is lots of variables in rebreathers in the market and what are you trying to do with the unit. I am not sure that I would want to take the Poseidon scrubber to 500 FSW.

 

[Wibble]

I only picked 150m/500ft as a silly depth beyond just about everyone's skills.

In the UK we have a lot of wrecks in the MOD1** recreational level and MOD2 (70m/230ft) range. With the cost of helium, you don't need many deeper dives to justify using one on a cost basis. This is a whole topic for a dedicated thread.

My point is that most rebreathers are capable of diving trimix out of the box with no additional cost; this is a perfectly reasonable thing for safety at recreational levels from 30m/100ft to 40m/130ft. Similarly, decompression diving is very natural at those depths. I do not understand why anyone would want to buy a unit that has such restrictions built into the unit; 18m/60ft is Open Water levels and everyone knows how restrictive that is.




** MOD1
The entry level rebreather course that all rebreather divers must do. The max depth depends upon the diver's abilities + experience and is given by the instructor at the end of the course. This will be a fail -- has to be mentioned as rebreather diving is difficult and requires moderate skills -- or one of 30m/100ft on air diluent, 40m/130ft on air diluent, or 45m/150ft on light trimix and light decompression.

MOD2 is the subsequent course for deeper diving on trimix and with decompression with two bailouts down to 60m/200ft or 70m/230ft depending on the agency. This course requires good skills especially with buoyancy under stress.

 

[formernuke]

Because all the cool.kids are doing it

 

[ND5342]

I only picked 150m/500ft as a silly depth beyond just about everyone's skills.

In the UK we have a lot of wrecks in the MOD1** recreational level and MOD2 (70m/230ft) range. With the cost of helium, you don't need many deeper dives to justify using one on a cost basis. This is a whole topic for a dedicated thread.

My point is that most rebreathers are capable of diving trimix out of the box with no additional cost; this is a perfectly reasonable thing for safety at recreational levels from 30m/100ft to 40m/130ft. Similarly, decompression diving is very natural at those depths. I do not understand why anyone would want to buy a unit that has such restrictions built into the unit; 18m/60ft is Open Water levels and everyone knows how restrictive that is.




** MOD1
The entry level rebreather course that all rebreather divers must do. The max depth depends upon the diver's abilities + experience and is given by the instructor at the end of the course. This will be a fail -- has to be mentioned as rebreather diving is difficult and requires moderate skills -- or one of 30m/100ft on air diluent, 40m/130ft on air diluent, or 45m/150ft on light trimix and light decompression.

MOD2 is the subsequent course for deeper diving on trimix and with decompression with two bailouts down to 60m/200ft or 70m/230ft depending on the agency. This course requires good skills especially with buoyancy under stress.

You can configure and buy and a Poseidon (Sport even) to make those dives right from the get go. You just need to purchase the right battery and counterlungs. I just configured a Sport to do just that on the US website and it came in under $10K. Their REC edition is even more because it adds the backcover which you do not need. I also configred one to make light deco MOD1 dives and it came out to be a little over $7200. Upgrading to the M28 computer is the most expensive upgrade but divers have been doing decompression dives with the paddle for years.

The TEC edition configuration makes you purchase their backplate and wing (crazy expensive) and adds other pieces that are not neccesarily needed.

 

[RainPilot]

So the Poseidon philosophy in its initial offering was to make it a very friendly Recreational Rebreather that could be later configured to a more technical unit. With that, PADI along with rebreather manufactures from Poseidon, Hollis and APD set out to create a recreational rebreather training program for a recreational type of rebreather. Without going into too much detail about what makes a recreational rebreather, the first level of training allows the rebreather diver to dive the rebreather to 60 FSW without an external/additional bailout cylinder. However, a bailout valve in addition to an octopus/safe second regulator is required. The Poseidon is unique in that the computer is monitoring the gas supplies and will let the diver know via the display if they need to move shallower or abort the dive based on the amount remaining of diluent supply. In fact, during the precheck tests you need to test the BOV and the computer then monitors the diluent supply being utilized to pass the test. If you are plumbing your BOV to an offboard bailout cylinder I am not sure how one would pass this test. Perhaps in the configuration settings with a tech type battery. Perhaps @RainPilot could fill us in as I know he has been taking his on deep dives.

Hey there.

Yes, you can plumb your BOV into a separate bailout which then becomes a dilout (diluent and bailout combination) as the unit ADV works from the BOV. I use a quick disconnect, start the unit plugged into the onboard dil and once I am ready to dive I switch to the dilout bottle. Dil bottle then functions purely as a wing inflator gas.

As far as Seven Sport vs Rec vs Tec, it's all the same unit, with different options, all of which can be swapped out/upgraded later on. The M28 is a very nice option, as Turk said the paddle is fine but the M28 is much more useful, it is a very good OC computer as a standalone as well. All the Seven now come ready for solid state sensors, you decide based on budget whether you need one or two.

As far as battery goes, I would spring for the black battery from the get go, its about 30 USD more than the rec green when you buy it with a unit and then you'll never have to change again. The rest of the Tec upgrade is cylinder inversion kit so you can easily reach the valves in case of a boom, and larger capacity lungs with manual add for O2 and Dil.

@WOB0.01J drop me a line before you buy if you want any advice, I can also hook you up with a more customised setup than Poseidon offer direct on the website (my signature may give you an idea why I can do that )

Also happy to chat Poseidon with anyone who has questions.

brendon at desertreefdive dot com

 

[RainPilot]

I am not sure that I would want to take the Poseidon scrubber to 500 FSW.

Richard Pyle and Brian Greene regularly take their Poseidons to 140-160m, in fact they are in American Samoa right now discovering new fish species as we speak. They've been diving the units to these depths for years now, without a single bailout in anger so far.

 

[berndo]

I just configured a Sport to do just that on the US website and it came in under $10K.

Yikes, that's more than a dive-ready JJ.