Discover Scuba Diving St Croix or St Maarten?

My husband and I are interested in the Discover Scuba Diving excursions offered by Royal Caribbean in both St Croix and St Maarten. Has anybody experienced either of these? Which one is better? How long do they spend in the water? We were thinking maybe do it in St Croix and then do the helmet dive or snuba in St Maarten, but there is also Buck Island in St Croix so we are stumped.

After asking several questions about diving in St. Croix and contacting several dive shops, the only consistent thing we were told was that diving the wall is a must. So, see if the discover dive includes the wall on the northern side of the island. If so, I would say do it, if not, you may want to wait for St. Maarten.