Did your friend give specifics as to what type of water pollution or what they saw? We spent 2 weeks on Caye Caulker over the holidays this year and we found it lovely. However, one must have the perspective that the island is quite small, the infrastructure is limited and there is a presence of trash in some areas. Overall, the water around the island was clean and clear. Understand, close to shore, there is sea grass and generally not swimmable from the beach/ shore. However, with so many piers and docks, accessing the water from there is easy. I recommend finding lodging that has their own pier. The Split is now repaired (was under construction when we were there) and they have a nice swimming area inside an artificial cove. There is also the main beach in the center of town and depending on the currents and sargassum, can be a very nice spot to swim directly from the beach. As for drinking water, drink bottled water, as one would in any developing country. Belize is beautiful and Caye Caulker is a charming and mellow place. If you go, no worries, just get in the groove of the slow pace and relax.
Did you drink cocktails with ice?
We always ditch and refreeze the ice in rental kitchens using purified water just in case but assume that the ice served in drinks at restaurants that cater to tourists is safe.
I did have fruit juices with ice for breakfast, sodas and iced tea without a problem. Also, The hotel provided unlimited filtered water which was nice.
Thank you. That is same consensus o am getting from a lot of folks. I believe my friend must have become I'll from something else.