There are many reasons there are fleets on boats in the BVI and a few other places. You will find few boats in the keys and even in southern Florida. The cruising grounds are just not conducive to enjoyment for those on a short term charter.
The Dry Tortuga's are nice to visit. There is nothing out there but birds. We have done the Dry Tortuga's from Key West and Sarasota.
The more boats for the charter. The better the cruising grounds. I would use that as a seeing eye dog.
Here are some sample itineraries:
http://floridayachtandcharters.com/destinations/destination-key-west.html
