How to start a charter business

We are interested in starting a charter business with the purchase of a 50 foot sportfishing yacht that is currently located and registered in Mexico. I have done some research and I understand that a boat must be built and registered in the United States to legally carry passengers for hire. The boat we are buying was built in the U.S., but it was taken to Mexico when it was first sold and has always been Mexican flagged. Assuming we transfer the boat to U.S. documentation after we take delivery, would there be any legal restrictions against operating the boat in a charter business?
Our reader’s preliminary research is accurate. Federal law requires a vessel to obtain a “Coastwise endorsement” on its Coast Guard Certificate of Documentation if it will be carrying passengers or cargo for hire within the United States. But a boat is generally not eligible for a Coastwise endorsement unless it was built and registered in this country.