What I usually do is go to Google, then search: city name (i.e. Cozumel),best restaurants, reviews
(sometimes I change the wording a bit.)
Then I read different restaurant review sites, newspaper and magazine articles. When a particular restaurant comes up on two or three different sites, I then read carefully the reviews and make a decision. I have never gotten a bad meal this way. Our cruise to Alaska this summer we did that and had an amazing meal at Matisse Restaurant in Victoria.