D_B:
Stephen Ash ... thanks , I llike the idea of the swivel (a well engineered one like KM) on a long hose better than the elbow.
I think that a swivel and running it under my arm is what I will do
I have my primary on a 40" hose routed under my arm (with a bungeed backup). This is strictly for OW diving -- not appropriate for tech diving -- but I think thats what you were asking.
I'll offer some advice from my experience from using this configuration for the past couple of months, you can take it or leave it.
First, instead of a 360° swivel, consider a 90° elbow. The elbow will give you two separate but complementary axis (axises? axii?) of rotation. So the reg already has a rotation up/down (all regs do). Then the 90° elbow will give you another rotation left/right. The combination of the two rotations is perfect for a reg that will normally be your primary and it spins around perfectly if you donate it for an OOG. Plus IRL it really never winds up in an odd orientation. Here is the Zeagle elbow I use, Larry can order it if you can't find it elsewhere.
Zeagle Elbow, Zeagle part #340-1003.
Second, 40" routed under your arm is a good length to deal with. It's long enough without being too long for underarm routing. You can swim side by side (donating diver on the left works best but isn't essential), and 40" is about the minimum length you'd want for that situation. After testing this in a pool, I definitely understand the DIR tech method (5'/6'/7' wrapped hose) because more is better in an OOG. I'll probably go to this at some point, if only to get a better feel for deploying with the wrapping method, but 40" works fine for OW for the time being. As it turns out, 40" hoses are easy to find, because its the standard length hose for a stage bottle. And if you go tech later, that hose isn't a throwaway.
Third, having that primary on a 40" hose will be a pain suiting up, your reg will either lay on the floor of the boat and get smashed, or it will drag in the muck for shore diving. This would be even worse with a longer hose. So I keep my primary clipped off on my right D-ring until I'm ready to hit the water. DIR divers do this with an attached bolt snap with cave line where the the reg attachment meets the air hose (
link to GI3's setup). Right now I'm using a
DiveRite Octopus Holder to clip off the primary when suiting up, etc. I keep the holder itself attached to my right D-ring pretty much at all times, the reg mouthpiece goes in and out of the bungee only out of the water. I tried to leave it attached around the mouthpiece for diving but the plastic bolt snap winds up too close to the mouthpiece. Anything that gets in my way is bad enough, but it was a bit of a Charlie Foxtrot in a test OOG, so I changed that right away! The DIR/tech way with the bolt snap and cave line seems better since the attachment is far enough away that the bolt snap isn't near the mouthpiece and the mouthpiece doesn't get stressed unnecessarily. FWIW, the bungee on my DR "octo holder" is already showing wear after a couple months. I'll have to try the DIR way in the water with the elbow before deciding, but I suspect -- like most of what they do -- they do it because it works.
Last, the bungeed backup is *great* in the water (which is the real test) but you'll need to lose your snorkel or trade it for a pocket snorkel. As much as I really like this configuration (the bungeed backup), even without the snorkel I find its adds yet-another-step for donning/doffing your BC or BP, and with a snorkel you basically need to remove your mask before you can take off your backup, and I prefer to leave my mask on. Personal preference, yada yada yada. Truth be told, I hate long surface swims anyway and do them on my back where possible, so this really wasn't a hard adjustment to make.
Anyway, just my two psi, YMMV, etc, etc, etc. As I'm sure you know, whatever you decide on, its better to decide in the water than on dry land.
