...well, for starters, they come standard with dual-convertible Yoke-DIN tank valves, you are free to use either a DIN or Yoke 1st stage as you wish, then ask yourself a few questions:
--will you be in an overhead environment, if 'YES' definitely use a DIN 1st-stage.
-- what fill pressures can you achieve locally ?..... all the liveaboards I've done only do 3000 or so PSI fills, DIN isn't really needed in those conditions, unless you encounter an overhead environment.
-- if you fill tanks at the shop, then load the boat, you can likely obtain good 3500 psi or more fills, I'd likely opt for a DIN 1st stage.
-- what is the pressure rating of your Yoke attachment of your 1st stage ? ...the more modern your reg, the more likely it is to be rated for higher pressures...personally, if open-water recreationally diving, I'm fine using a recent modern Yoke 1st-stage up to about 3500 psi, just make sure the tank-to-reg O-ring is good, pressurize it and check for any leaks....remember the tank pressure will soon drop below 3500 psi anyway as the dive progresses. If you're really paranoid and worry about overloading your Yoke attachment with a HP fill, only pressurize your reg just before diving, to reduce the time-under-stress factor.
I've got a few DIN regs with some pretty slick SCUBAPRO DIN-to-Yoke adapters attached....... in 2 seconds I can switch one of these regs from DIN to Yoke or vice-versa, I'd recommend you go that route to achieve the flexibility to deal with any tank you encounter.
Karl
Well, I am not doing overhead environments. Just outside and around the wrecks. Why is this a factor?
Locally I can get a full 3500psi fill no problem. Nitrox, Tri -mix tec. My LDS is where alot of the serious/psycho wreck divers go for equipment, fills, etc. He just wants almost $400 for a steel HP 100. Ouch.
My first stage is relatively new so it is probably good to go but I will check with my LDS. Ralph has my regs right now doing an adjustment on them so I will ask him when I see him.
If it looks like a problem, I'll just get a the converter for the first stage, DIN for wreck diving and switch over to the yoke when tropical diving in the craibbean where it's all AL80's.
Thanks for the reponse!
Edited by CaptSaaz, 21 February 2006 - 09:31 AM.