Any department store, discount store, or drug store that sells sunscreen will probably have this. It's usually in a bottle with a pump spray top (not aerosol) and is in the same area as the regular sunscreen.
There was a little cabana @the pool of the Dolphin and Swan and they had some natural tanning lotion. I hate the regular stuff that when you get it in your eyes it burns. It was expensive but AWSOME. I don't know if you are doing a land and sea but it might be worth a bus ride.
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