Castaway Cay has a couple of Areas with their own Area Music. The first one that guests are exposed to is at the arrival plaza. This can be heard from the veranda if your stateroom faces the island, or from any of the open decks on board. Once exiting the ship, it can be heard as you walk toward the trams and fades as you get further from the ship. The music is coming from a small building resembling a shack, (Called the "Pump House" visible immediately upon exiting the ship. My reference recording was taken from my veranda, but parts are obscured by heavy equipment, such as forklifts. This created enough background noise to give me only a few words at a time, and certainly not enough to let Shazam have a go.
I'll keep digging on those five other reggae songs and hopefully can fill in the blanks shortly.