I'm neither a lawyer or a licensed captain, and I didn't even stay at any hotel last night.
But I'm a sailor and therefore have an opinion
All of 46 U.S.C 2101 applies, however the most pertinent parts are perhaps 21a and 5a.
The have slackened up in recent years so that friends going fishing, day sailing etc. are not considered a commercial enterprise, but this is clearly not the case here.
You are in fact offering at least partial compensation but have expectations on directing the boat (hanging out at islands for set periods of time, directing locations).
That's for US skippers - and applies in US waters. Other countries will of course have their own laws.
Bottom line is the skipper/owner of the boat offering the ride is the one that is taking the risk here.
A boom going errant and slapping a study member on the noggin can result in a lawsuit that can end a retirement sail off into the sunset as easily as a hurricane.
I'm not saying you won't find someone who will take you - maybe even a licensed and insured skipper; in fact I wish you all the luck you need.
for 440k, heck, buy a boat for 50k and rent a skipper