If all are US citizens, just clear in--Cruz Bay on St John is easier than Charlotte Amalie on St Thomas Everyone on board will need to go to the Customs
office "for inspection"
Here's some detail from the govt website: Puerto Rico and the U.S. Virgin Islands - CBP.gov
"The Master of the vessel must call to report arrival immediately
upon entering the United States by calling the nearest designated location and provide:
- LBO registration number (if applicable)
- Name, date of birth and citizenship of all persons on board (including passport number)*;
- Name of the boat and/or boat registration number;
- CBP user fee decal number (if 30 feet or longer);
- Homeport and current location;
- Return contact number
*Beginning January 31, 2008, U.S. and Canadian citizens 19 years and older who enter the U.S. at sea ports
of entry from within the Western Hemisphere will need to present government-issued photo
ID as proof of identity along with proof of citizenship. By summer of 2008 it is anticipated that only passports or WHTI-compliant documents will be acceptable for entering the United States."