PITY! I will be there the following week. Probably, cross each other in the reception area

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The watersports hut (I think) closes at 5pm - hope your arrival will be in time. If close, leave someone to check in, and you head off to watersports.
The better dive is normally the 9am dive, while the 11am is generally for check out and resort divers. Usually, I do both regardless. You can sign up for your whole week in advance. A bit unfair, however, if you don't use the slots as sometimes there is a numbers restriction and divers are turned away. Frequently, B. Sandy Bay has more divers than the larger B. Negril (adults only) whose guests tend to indulge a bit more at nights (my speculation).
You might want to take your own regulator. I found many of the hotel's to be in need of servicing (they have a rough life), mainly little leaks and chewed up mouth pieces.
Don't expect the fish life of Cayman (although a couple yrs. back a pod? of dolphins took up residence there). There is still a lot to see - turtles, eels, lionfish, nurse sharks,squids, rays, schools of goatfishes, grunts, and creole wrasses - just not with the frequency of renown dive destinations. Then there are the sponges, sea fans and gorgonians -all this in warm, calm (mostly), seas with good vis. - very pleasant and ridiculously easy.
The DM's are in the main very pleasant and they do try to please within the strict rules (depth/time) laid down by management. Be patient with them and use your smile a lot.
Additionally, if you have kids, there is a water park (slides) opposite B. Sandy Bay.
If you have other questions, feel free to PM me.
Have fun.