You might be in luck and the resort won't be full. If occupancy is low I'm sure they'll move you guys around to accomodate your needs.
You might not get the rooms you want when you arrive, but they can usually do something next day.
Last Jan when we went away with all the kids, we had to wait a day and then they moved us all into the new section of the resort and gave us adjoining rooms.
How big is the resort? Is it a long walk to the beach from the South side? Where is the dive shop? I guess it's better to wait until you get there and then decide where you want the rooms?