... All my seconds are break away and readily accessible to all. The one I wish to donate, or have taken, is marked with yellow tape on the hose and on a yellow loose necklace just above the inflation valve (dry suit).
Please read the previous very possible scenario description : ... you can't see (silt, no light) single file on the line in narrow cave passage or shipwreck hallway.
---------- Post added August 1st, 2013 at 03:35 PM ----------
Ok, so I will summarize !
So for given scenario: no lights, no viz (silt) condition, holding the line with one hand for dear life, one diver is out of gas, but when reaching for dive buddy regulator its a 22" necklace - ZONK !
Happens that donating diver had two independent sidemount cylinders.
So here are the most heroic answers (no names)
1. having two long hoses, which as we discussed would create a multiple hose crossings, and depends on donated hose being cut off by the other stowed at the time long hose
2. some wrote that in complete pitch black black out will somehow signal to the buddy that he should wait (have no idea how long) and the donating diver will detach the tank and again in complete darkness
pass the tank with regulator (using one hand, other on the line) to his OOG buddy, hope his buddy wouldn't loose any teeth or end up with crushed skull after getting hit by steel tank, and his OOG one handed buddy will catch the reg with the tank and rescue himself !
WOW ! YOU GUYS ARE SIDEMOUNT SUPER-HEROES !
Even as a UTD instructor I just realized that I have to still learn so much !
So my answer again is simple, just donate the long hose and always long hose as you were trained to do in backmount and lets swim back home !
ANSWER TO VERY OFTEN BROUGHT FAILURE POINTS:
Any piece of equipment is a failure point, fin strap, mask strap, going through hose connections, valves, lights etc. Have you noticed that even without having isolatable manifold we (divers) will differ with "possible failure points" on regular basis. for example I dive drysuit and argon bottle, other wetsuit and no argon, its counting two ends of the hoses few more or less possible failure points.
Remember as long as something has a proper procedures that team is thought we can solve any arose problem and just go home safely regardless if we have 4 or 6 hose connections etc.
Still advantages of UTD isolateble manifold are way grater then cons.
Cheers.