You can rent boats in Nassau at the British Colonial Hotel by the beach next to Senor Frogs. Not a very well known business, but I rented there once. I did lose my security deposit, but I deserved it. (High tide, low tide, who knew)

You might also try Captain Viking Tours on Facebook. Captain Andy takes you out on his boat to Rose Island or wherever else you want to go. Very affordable. Ask him to take you to Sandy Toes on Rose Island.

Probably best to do something like a "sailing charters nassau" search on Google and start with results there. You might also try a new service caleld Quora.com and see if the community there has any ideas.