News- Deep Dive 650ft

[PerroneFord]

Honestly, the costs aren't THAT bad for some of the units. I am not a rebreather diver yet, but spend quite a bit of time around rebreathers and rebreather divers. With the KISS sport hovering around $4k, it's not hard to see that if you are spending 4-6 hours a weekend breathing trimix on open circuit, the gas costs are going to equalize pretty quickly. A set of new 130s is over a grand. Unless you have easy access to a trimix fill station, you're going to be taking more than 1 set of doubles. Now you're halfway to a KISS unit.

Of course the Ourboros is in anohter league, but it's kinda large (and delicate) for tight cave work anyway. Seems like the Meg has a nice sweetspot. I'd LOVE one someday. But then I like the KISS too.

...sorry to butt in on your thread.

 

[FIXXERVI6]

My issue with rebreathers is the bail out gas, ow, wreck, you don't have to carry too much bail out no big deal, but for long cave penetrations, kinda sucks, I want to dive rebreathers in a doubles configuration, if one rebreather fails switch to the backup rebreather and exit the cave.

 

[amascuba]

My issue with rebreathers is the bail out gas, ow, wreck, you don't have to carry too much bail out no big deal, but for long cave penetrations, kinda sucks, I want to dive rebreathers in a doubles configuration, if one rebreather fails switch to the backup rebreather and exit the cave.

The Halycon Semi-closed circuit rebreather was built with things like what you mentioned in mind. It uses double cylinders and a modified isolation manifold that will allow the diver to switch to open circuit and have enough gas to get out the cave, completing a full decompression obligation.

 

[texdiveguy]

My issue with rebreathers is the bail out gas, ow, wreck, you don't have to carry too much bail out no big deal,

Rick I am losing you on the o/w and wreck dives (assuming you are taking tech deep o/w and pent. wreck profiles),,,the concerns of bail out gas is just as important as in cave....whether open circuit or closed or semi-closed. ???

 

[loosebits]

Rick I am losing you on the o/w and wreck dives (assuming you are taking tech deep o/w and pent. wreck profiles),,,the concerns of bail out gas is just as important as in cave....whether open circuit or closed or semi-closed. ???

In a wreck, if you spend 20 mins inside, that doesn't mean you are 20 mins from the exit. You may have spent a lot of time swimming back and forth checking out compartments. It may only be 5 mins to the exit and then you can begin your ascent.

In a cave, you generally spend your entire time penetrating further into the cave so its going to take that entire time to come out. Big difference.

 

[texdiveguy]

In a wreck, if you spend 20 mins inside, that doesn't mean you are 20 mins from the exit. You may have spent a lot of time swimming back and forth checking out compartments. It may only be 5 mins to the exit and then you can begin your ascent.

In a cave, you generally spend your entire time penetrating further into the cave so its going to take that entire time to come out. Big difference.

I fully understand that,,,but the concerns of having ample supply of a 'bail-out' gas is just as important. Rand I do understand though about the distance within a cave run and an exit.

 

[loosebits]

Yes, you just don't need as much (which I believe is his point) in a typical wreck or OW dive because the distance needed to get to the surface isn't as far. In a major wreck, the distance to the surface (depth + distance to exit) is measured in hudreds of feed. In a cave, it is measured in thousands.

Rick doesn't believe RB's are practical in a recreational cave dive because of the amount of bailout gas each diver would need to cary to make the exit. I see his point but I don't think that's common practice. I believe most RB cave divers just make sure there is enough bailout amoung them for some of the RB's to fail, not all of them. In a team of 3, if the amount of bailout judged necessary was to deal with one failure at max penetration, each team member carrying a single 80 would be enough gas to justify the same length of penetration using OC as could be achieved with nine AL 80's.

Now, if we could afford bailout rebreathers

 

[FIXXERVI6]

I fully understand that,,,but the concerns of having ample supply of a 'bail-out' gas is just as important. Rand I do understand though about the distance within a cave run and an exit.

ok then do the math, its real easy, your in 130 feet of water, your 5 minutes from your ascent line, how much gas do you need to exit.

now your in a cave, lets say your 2,000 feet from the exit, in 60 feet of water, do the math.

no where did I say you didn't have to have ample amount of bail out gas in a wreck, what you missed is the amount of bail out gas you have to carry in cave penetration is a lot more than you need to bail out of a wreck.

 

[FIXXERVI6]

I met some RB divers diving caves in florida, they pushed in teams and the team carried enough bail out gas for 1 diver, this is going back to what loosebits is saying, so you don't have to carry all of your bail out gas, your team carries it for the RB diver that fails, I'm not all that hip on the idea, if its the way it has to be done then it is the way it has to be done, but I saw where the UK WkPP people (I think that was the group) dove their rebreathers in a double rebreather configuration, they would burn some one one breather, then swtich to the other, back and forth like indipendent doubles, that took away the need for bail out gas, now thats awsome, but WAY beyond $$.

 

[amascuba]

I met some RB divers diving caves in florida, they pushed in teams and the team carried enough bail out gas for 1 diver, this is going back to what loosebits is saying, so you don't have to carry all of your bail out gas, your team carries it for the RB diver that fails, I'm not all that hip on the idea, if its the way it has to be done then it is the way it has to be done, but I saw where the UK WkPP people (I think that was the group) dove their rebreathers in a double rebreather configuration, they would burn some one one breather, then swtich to the other, back and forth like indipendent doubles, that took away the need for bail out gas, now thats awsome, but WAY beyond $$.

I believe those guys use an EDO rebreather. The EDO is just a Halcyon RB80 clone. It's basically just a canister/counter lung setup and you can configure it from there anyway you want. I've seen people put the canister on a bp/w setup and a STA with bands coming off the canister to attach double cylinders. The clyinders can be anything from AL80's to steel 130's. You can get, or make a isolation manifold for the clyinders or use them as independant cylinders. You would use two regulators with an extra low pressure hose(s) that feeds gas to the canister. In the event of a rebreather failure you would use the same gas for open circuit to execute your emergancy procedures. Using this method you would have enough back gas to get you out of cave/wreck/deep dive on open circuit in the event of a failure. (You would also use open circuit deco gases like normal too) You can also use two EDO canisters for redundancy or to even extend the dive if your canister's scubber doesn't last long enough for the dive you have planned. It's pretty cool stuff. You can check out the EDO website at:

http://www.stde.ch/en/edo04/present.php
http://www.stde.ch/en/edo04/options.php