[Arubalisa]

I think you could get by with the BC in your luggage. The reg and computer for sure in the carry on.

Not sure about weight "bags" but you could definitely come up with something in Aruba rather than lugging the weight. Heck a lot of divemasters I have dove with have carried extra weight in their pockets "just in case" someone couldn't get down.

You will be using more weight in Aruba than you did in fresh water in that you will be more buoyant (salt water is denser than fresh water ).