My mother in law is only in her 60's but is very fit and she did great for 10 days on a cat, my mom is in her mid 70's and very active (Golfer) but she would NOT be physically comfortable chartering even on a cat. Her knees are the problem...getting on and off the dingy would be a major problem, there are relatively steep steps leading to the cabins that would also be a pain for her. I would describe everything to your mom... dingy, swim ladder, getting on and off docks and if she says no problem I would go to the BVI!! Good luck <img src="http://www.traveltalkonline.com/forums/images/graemlins/Cheers.gif" alt="" />