Allow me the clarify, if it is the standard octo length there would be a big bow of hose outside your profile. This tends to catch on things or rub up against your buddy or the environment. So yes I see a problem here to put it bluntly.
How is the "bow of hose" any different in Configuration A in which the octo is held in a rubber necklace than in the traditional PADI-sanctioned Configuration B in which the octo is held in a conventional octo-holder (whether ball, snorkel keep or whatever) attached to a BCD D-ring? In Configurations A and B the octo position differs by only five or six inches. Whether it's under my chin on the necklace or a few inches to the right or left on a D-ring seems trivial. In both Configurations A and B the octo is still more or less within the so-called golden triangle.
DaleC in post #59 says octos in rubber necklaces hang too low, but it seems in the right place to me.
If an OOA diver is going for your octo, it's in a uncommon spot. Your buddy may have no trouble if he's been briefed, but a non-buddy or panicked buddy will have some trouble identifying.
The octo is yellow and has a yellow hose, so I would hope the OOA diver would reach for that one. However, in the event the OOA diver pulls the primary out of my mouth (which I can assume he would do regardless of whether it's Configuration A or B), can't I simply grab the octo that's under my chin and put it in my mouth? I mean, if he grabbed the reg out of my mouth in a traditional Configuration B, I'd have to reach for the octo on my D-ring anyway and put the Octo in my mouth. So what's the difference really? I'm not trying to be argumentative--I'm just trying to determine if there is any cause for concern with what I'm doing (above and beyond any concerns there may be about the traditional PADI-sanctioned golden triangle donate-the-secondary configuration). I know at least one other person posted here that he does the same thing. Morever, since yellow rubber necklaces are available, I suspect many other people are doing this, too.
So I don't see a benefit in having the standard length octo bungeed to your neck.
Ah. The benefit that I perceive, however minor it may be, is that I believe I can find and grab the octo under my chin faster than I can take it out of the traditional octo-holder on the D-ring (if the OOA diver doesn't grab it first), even though the difference in locations is only a few inches. I always seem to fumble for a second when I need to locate the D-rings and whatever is on them--I don't have an intuitive feel for where they are on my chest. But if something is hanging from my neck, I can somehow put my hand on it immediately. Maybe it's mostly psychological: I just like the idea of having something so important as an octo right there in front of me where I can keep an eye on it, not a few inches off to the side where it's often out of my field of view.
If you have trouble finding a secure method for your octo (aside from the necklace) I would suggest making a loop out of 3/16" bungee or using a snorkel keeper. Loop it around a D-ring and hook the mouthpiece into the loop; wrapping it past the zip tie notch.
I've tried all kinds of octo holders, including the snorkel keeper method, and I eventually went back to the common "ball" type. I hate them all. Some release too easily, some are too difficult to release, some let the octo flop around, etc. The rubber necklace seems to address the things I haven't liked about other octo holders. That said, the donate-the-primary configuration does seem to be better than either A or B.
