you may want to contact Soundings, they have a commercial monthly (I think) rag and an on line presence for those in the commercial side of boating.
There really is not much magic in being a charter operator/owner...in the US..
License 6-pack or higher
appropriate business license
ability or talent in dealing with the public
ability or talent in dealing with high strung people
ability or talent in a service industry
all the rest is just another business. BEen there done that.
If I were going to do it, again...I would find "older" reliable boats and market them to plain joes, with some sailing experience..at daily rates and week rates...not the fancy vacation stuff..just someone who wants to enjoy a sail...YOu would need a few helpers or an arrangement with a marina/tow..but you could buy a half dozen USED boats for what one "charter boat" would cost.
Depreciation would be zilch, you could almost do this as a one man operation if you only 3-4 boats.
I think you will find it quite difficult to compete with those larger/more well known operators. Their advertising budget was more than my yearly cash flow...Unless you have a unique hook.
Best of luck, it can be a blast...