Regulations - Ask MTS
Starting a Charter Company
This voice of experience suggests that you would be well advised NOT to form a charter company in Antigua. Establishing a company in Antigua & Barbuda is difficult, archane, and usually involves 'grease' changing hands.
Antigua also has established itself as a place to avoid if you are aboard a yacht.
Consider setting up a company in Anguilla BWI, the BVI, or Delaware USA. All are reliable legal jurisdictions with clear laws and they completely understand the yacht and ship business. And yes, use a law firm to do this for you. Don't forget good banking and insurance requirements.