I managed to get myself invited to the BVI to sail a couple of times, and loved it so much that I took "Colgate Learn to Sail" and "Colgate Learn to Bareboat." I also took a local Coast Guard safety course. Next time I came to the BVI, my friend listed me as a co-charterer. When I sought to charter on my own the fifth time, I literally submitted a sailing resume which included prior sails, copies of my certificates, and copies of my previous invoices with that company. Sailing a 45 foot monohull is not a lot different than sailing a 18' learning sailboat, but as others have noted, it's all the other stuff - anchoring (although not as common in the BVI now), diesel engines, marine radios, marine heads, etc). But if you can find somebody to sail with once in the BVI, you will learn more than you can imagine just by doing so under supervision. And you will be hooked!