lol...
we just sold a 30 saiboat (moving up to 40 ish footer).
i have dove several times from it..a hassle, but not too bad.
I think you do not realize the ownership costs of a sailboat. A decent sized sailboat will not be trailerable so you will have slip rent $6k/yr here. you will need to clean the bottom monthly. You will need a haul out once at least every other year to repaint... this ran us about $1500.00 including the painting (we painted it).
If you need to replace the running rigging, $1K
If you need to replace the standing rigging, $1K
If you need sails $3-5K
if you keep it in the water you HAVE to visit it often just to keep mold under control... try not checking on it for a few months and see what happens inside.
the smaller the sailboat the slower. since sailboats are displacement vessels, so the speed is limited by the waterline length.
my 30 footer was limited to just under 8 knots
a small 22 footer would be about 6 knots....
something that small would be a major PITA to dive from.
here's a hint.
when diving from a sailboat, it is harder to get in due to the high free board...
shed your gear and let it float and attach it to a halyard. you can then use a winch to lift it into the boat.