Heather Anderson can sort your friends' wedding for them from start to finish, and using a planner will take out loads of the logistical headaches.
https://www.bvi-weddings.com/?fbclid=IwAR3ntkaA3EXCjUk7XZD-QTCb-vuzd2hsTjJtPgynUJsRpmYewfYlOZ4oAnwI think the main deal with Sandy Cay would be that you'd have to get a Registrar out there to perform the ceremony, and as you obviously know it actually can be tricky to access in a swell, and also can get super busy sometimes. But I'd talk to Heather, she's done tons and tons of BVI beach weddings.
