Arlene, remember we are in Bora Bora for two days, and overnight. Arrive at 8:00 a.m. on Thursday the 17, and leave at 6:00 on the 18th. Thats why I thought the 18th would be perfect for a morning snorkel sail, and the 17th would be good for a sunset cruise. We may be interested in the ship excursions, but usually they are much more expensive than chartering privately. With 4 of us, that is a concern!