We went to western Carribbean: Cayman, Rotan, Belize and Cozmel (Mexico) 3 weeks ago. No, my B2 mom came with us, no visa required to these places. I guess it's same to other islands (please check further).
Mom extended her stay and will fly back next month but her visa is still valid. The interesting issue is when we came back, we encounted a inexperienced us customs officer. When we passed over her extension approval, the officer said, no, you don't need to apply for that(he confused it with visa) as her visa is still valid. Then he asked us when she will leave US. We said, Feb, as the extened I-94.
Suprisingly, he issued a new I-94, with another 6 months!
BUT, don't take my case as a rule. This officer should NOT issue her a new I-94 according to the close-loop cruise policy.
Hope this helps.
