I agree with you all the way up to here, (quoted above)
Ask 15 disabled boaters on what could help with their boating experiences and you will get at lest 10 different answers, but one of those answers wont be I want to stay at home where it is safe and watch soap operas on TV., The last thing they want to hear is, "you shouldn't be boating" and as the carer of a wife with MS, who has been in a wheelchair for over 20 years, we have heard it often. We have even been reported to the marina authorities, and been banned from the pontoon at a sailing club.
You could also say disabled people shouldn't be in cars because they might be killed in a vehicle fire if they can't get out the car quickly enough. It's probably more dangerous for an able bodied person to drive a car than it is for a disabled person to be on a boat.