As on the mainland, certain professions require board certification to practice in the Virgin Islands. Certifications and licensing are overseen by the Department of Licensing and Consumer Affairs. So even if you buy a business on St. Croix, you will still need to seek board certification in your field, if you are in any of these businesses:

Architects, Engineers, and Land Surveyors
Barbers, Beauticians and Manicurist
Electricians, General Contractors, Plumbers, Construction Contractors, and Mechanics
CPAs
Real Estate Appraisers, Brokers and Sales People
Social Workers