Rec or Tec ... if you can’t get yourself and your gear back on the boat you shouldn’t be diving off that boat on that day. Otherwise it’s unsafe for yourself and others. If you can’t do it at all you shouldn’t be boat diving. That may seem harsh but no one HAS to dive. It’s a hobby and if you can’t do it self-sufficiently than you need to pick a different hobby.
The implied (but unstated) context to my post was a traditional non-limited recreational or technical diver. Adaptive diving was not the context I was discussing. Adaptive diving is an entirely different beast requiring training and planning for special equipment, procedures, etc. In my mind adaptive diving is a completely different class or type of diving. It's not recreational nor technical but adapted diving.
So explain to me this adaptive diving thing.. You gotta be missing a leg? Maybe paralyzed? What is it? When do you reach the magical "adaptive" diver level? When do you get to that different class of diving?
Scuba diving is pretty dang fun, lots of cool chit to see down there - can you handle yourself in the water, if the answer is yes, if people really wanted to, they could figure the rest out. I didn't become an instructor to become financially rich by any means, I did it so that I could show people what is below the water, see their faces light up after a dive. I can't wait to have our first disabled veteran dive with us - taking someone on their 1000th dive is business, taking someone that has a disability or difficulty - that's what it's about.
Someone has a bum knee and needs a hand - you adapt. Someone has a fused spine and can't even walk up a single 80 - you adapt. My wife has a fused spine, not a chance of walking up a ladder with a single tank on, she dives all the time - we adapt.
And before you even stammer on about safety - there's a good percentage of divers I see here that are heart attacks waiting to happen or that are at an age that puts them into high risk heart problems. In my lifetime, I've had three friends drop dead with zero warning, aneurysm's all three, all between 32 and 43 no prior health problems. How you gonna get a 200# guy back up in the boat? I'm sure you'll figure it out just like if you really wanted to, you could figure out how to help a person in doubles back up a ladder.
Adaptive diving requires a plan just like all diving does.