Some basics:
Red Sail has operations at several of the major hotels. The Hyatt, The Westin, The Marriott, The Courtyard by Marriott all along Seven Mile Beach. They also operate at Morritt's Tortuga Cluba under the name Tortuga Divers.
The Seven Mile Beach locations will either do a beach departure right from the hotel (Hyatt or Westin) or transfer you by van (other properties).
Boats generally are equipped to handle about 20 divers. All carry first aid and oxygen, and staff are trained to use them appropriately should the need arise. Most boats serve sliced fresh oranges and they provide drinking water and an ice chest for your use.
Red Sail uses 72cuft aluminum tanks. They have a very few 50cuft tanks mostly used for pool training.
Red Sail generally insists on guiding divers on deep wall dives. Shallow dives are often offered as a choice of buddy team or guided. Table limits are enforced if each buddy does not have a dive computer. That would mean 100ft for 20min and 60ft for about 35min with a 45min surface interval.
Red Sail is often cited as handling lots of cruise ship divers, but that is not currently the case. Such contracts periodically are rebid by the cruiselines, and currently Red Sail does not have major commitments in the cruise diving sector. It is of little consequence to the stay-over guest as they never were a business to combine cruise ship passengers on the same boat as stayover guests.
Red Sail has watersports equipment for rent at several properties, including jet skis. The operation at Morritt's in East End has the island's best (and only, I believe) windsurfing rental facility.
Red Sail also operates several beautiful large catamarans for sunset cruises or trips out to the Stingrays.