Been meaning to post my findings. We visited Atlantis in early June and did get a little time to do some monitoring.
As previously mentioned, there is a lot of marine activity with all the cruise ships and marinas. The Atlantis marina working channel is 10 (156.500).
Not too much public safety activity noted on the Nassau TRS (5934h) which is listed in the database.
Atlantis resort is operating a very large 800 MHz LTR system with Kenwood subscriber equipment. They apparently use a different 800 bandplan down there, my BCD396 wouldn't let me enter a couple of the repeater output frequencies (around 847.xxx). I actually had better luck searching the input frequencies in conventional mode.
Like I said, didn't spend too much time trying to determine their fleetmap, etc.... too many other distractions and fun in paradise!
Here's a short list of what I found for the Atlantis LTR system