In situation where I had to share air probably an OOA situation I would no be taking a long swim back to the ascent line, I would be making a emergency accent right where we are and would have though a 40" hose would work fine in this situation.
I once managed to get a VERY panicked OOA diver who was well off a wreck back to the ascent line safely, my 7' hose certainly made the job easier. Sure was nice bringing a panicked diver back to the boat and not having to babysit him for a long surface swim or force the dive boat to recall everyone, or worse, leave them hanging to rescue one diver.