I love the different water colors between the Caribbean Shelf and the "real" Atlantic Ocean.
Well, up on the Bahamas Bank the water is between 7 and 11 deep generally, the other side of the islands drops off into the deep abyss. There are a few nice staged walls up to a 30' reef then a nice shallow incline to the shore with coral heads that make for some spectacular diving with luminous ultraviolet sponges and all the different pelagics and reef fish together. I'll bounce down until it gets dark (around 300') and the come up, you get a great view of all the big fish hanging around the edge silhouetted against the sky above.
BTW, the Bahamas technically aren't the Caribbean, they are on a different tectonic plate.