Multistage and reg re-use

[Cindy]

I have had a buddy switch during a dive due to a regulator failure. It was a side mount dive and he was dealing with a new side mount diver as a buddy. (Me) It took place in a cave that was tight enough we couldn't really get out sharing air. Guess we hadn't really talked about how to switch tanks. He held his breath and was able to switch tanks with his remaining good reg. I was pretty much having a nervous breakdown watching him. (realisticly he may have been showing off just a little) I kept trying to get him to take one of my regs but he decided not to. Switching underwater can only be done on a few regs and requires that the reg be cleaned after. Not something you would either like to practice or do a regular basis or even watch. These days I either switch tanks which requires some practice or use my long hose that I keep on my tank. Don't even go there asking me why he had used the air out of one tank more than the other. Brrrr, bad mojo just talking about it! Not smart and not cool. Frankly I would rather solo dive than watch someone I care about drown. I dive a little smarter than that now. Cindy :{

[Moonfuzzy]

Well the question arose partially after looking at this picture: http://www.wraysbury.ws/index.php?na...lbum=16&pos=57

It looks like they are using one reg for each set of doubles attached to the diver - in a sense treating each set of doubles as a stage bottle. I don't think that the diver is moving regs around during the dive... there is no need. If he looses a reg he looses the set of doubles, but he has 5 or 6 sets attached and should have enough gas to get back home.

[FW]

Another big issue is time. It takes time to switch regs, and thus shortens the actual penetration distance. That was your main goal anyway, wasnt it

[Tegg]

ARY... if you have seen all the cave you can in one stage, time to either buy a second reg setup or a scooter...

I say go for the scooter...

[ARY]

I say go for the scooter...

Or two scooters, and 2 circuits Megladon with two VR3 controllers

Thank you all people for sharing your thoughts. And two people offered me regulators, that was really nice of you guys, really. No, i'm not going to hide cylinders in caves from my wife. This was started as purely theoretical topic. However i carry regulator set on the right bottle H-valve of my sidemount cylinder just for that purpose: possible UW wet swap. I also practiced breathing from valve in A spring after my "stress from rescue" OW course although i'm not sure if i could swim like that in a cave. Just one more thing: when do wet swap one should watch that o-ring at the end of DIN, this thing easily flies down to silt.

[NitroxWarrior]

sheesh thats too many tanks, invest in a rebreather and a big scooter...

[rchrds]

Just one more thing: when do wet swap one should watch that o-ring at the end of DIN, this thing easily flies down to silt.

Just a note on this for everyone- over a number of years of dealing with different regs- MANY, MANY shops do not replace this DIN oring with the proper oring- many shops use a rougly equivalent non-metric oring. The only difference in fit affects what Ari mentioned- The DIN orings do NOT fall off the regulator. They fit snugly on the inner dimension, where almost all DIN regulators have a concave face, for the express purpose of retaining the O-ring. The non-metric oring is squished inside the outer dimension, which does not hold the oring adequately. The proper oring size for a DIN regulator is 2.5 x 11mm. All the manufacturers kits will have the proper o-ring, but replacements for O-rings lost in action will almost never be from a full kit. Ask your shop tech- if he tells you that a 111 will work OK- he is wrong, and you are reaping the benefits.

J