We just got back from a cruise in the Caribbean. It was really interesting seeing where the sea glass was, and wasn't! Paradise Island in Nassau was pure pristine white sand. Now, if you looked closely, you could find the most beautiful shells. They were bright pink and yellow. I've never seen shells like that before. But sadly, there was no sea glass.
Later on in the cruise, our ship couldn't tender at their private island, so we went back to Nassau. This time, we walked off the ship and along the shore to a beach that wasn't nearly as nice and had construction nearby and smelled bad (what a beautiful mental picture I'm painting), but there were rocks AND SEA GLASS! It was everywhere. Most of it was junky beer bottle glass, but every now and then I found some beautiful, old, frosty pieces! I found two pieces of black glass too.
So even though I wouldn't necessarily want to spend my vacation there, it was the perfect place for sea glass hunting. We did the same thing in Grand Cayman. We went to an out-of-the-way local beach that was small and found so much sea glass! It was called "Cemetery Beach". It also had a decent, small reef right off the beach that we snorkeled at. The kids saw a sea turtle and some beautiful fish. If you're used to reef diving, you might be disappointed, but for the kids it was perfect.
So the take away is: look in unexpected places in the Caribbean for sea glass. Don't just go to the main, popular beaches and expect to find treasures.
Happy sea glass hunting!