Investigando he encontrado esto, al que le pueda interesar:
"An alternative method on entry for crew without visas is to make use of the Visa Waiver Program (if they are eligable) by first taking a ferry trip from the BVI's to the USVI's. This has been confirmed as perfectly legal and will then allow crew to enter the USVI again or Puerto Rico by yacht. It is, however, essential that they are in possession of a valid ESTA (Electronic System for Travel Authorization). Once granted, an ESTA is valid for 2 years. Entry under the VWP permits visits of up to 90 days from the date of the first entry into US territory."
Fuente:
http://www.noonsite.com/Countries/Pu...rc=Formalities
Aunque no entiendo muy bien como funciona, si entras con Ferry y el ESTA supongo que te danla visa por 90 días y entonces puedes entrar en Puerto Rico en tu barco privado...