The thing is that the Gulf coast of the peninsula is know to serve up the finest seafood anywhere in this region - especially shrimp - and there's possibly only one other joint in Campeche where I would perhaps prefer to partake of it. (For another day...)
The Coctelería Cajun is traditional, basic and very popular; the apparent cheapness of the decor and associated ambience ought not to deter. Wooden tables and chairs are crammed into a walled off front yard with an especially high turnover between midday and the late afternoon.
A few caveats vis-a-vis my earlier, rather disparaging remarks about the location. The Isla del Carmen sits on the beautful Laguna de Términos just shy of the point where the peninsula bleeds into Tabasco. It is linked by an undulating causeway to Isla Aguada to the north, which is indeed a perfect place to take in the charms of the more unspoiled stretches of Yucatán coastline.
The city itself has a compact historical casco with some fine pastel-painted casonas worthy of the state capital itself.