Not many of us think about checking out a Mexican restaurant when we feel like tucking into a stuffed crab-back and sucking the heads of prawns. Perhaps, being stone crab claw- and Key West pink shrimp-centric, we haven't had the exposure necessary to inspire such appetites. Or maybe, being offered mostly central Mexican cuisine here in South Florida, we simply haven't had opportunity enough to appreciate the fact that Mexico has a cuisine deriving from a couple of thousand miles of coastline -- and that's just on the Pacific side, where the town of Puerto Vallarta is located. Fortunately our education is at hand via El Puerto de Vallarta, and we're not just talking about the three R's of fish tacos, but the ABC's as well: avocado-garnished shrimp and snapper ceviche with pico de gallo; botana (appetizers) including shrimp quesadillas and oysters on the half-shell; and seafood caldos (soups) such as the piquant mariscos siete mares, a luxurious combination of seven different types of shellfish served with homemade corn tortillas. Finish off your secondary schooling with bacon-wrapped shrimp or garlic-sautéed lobster and a cool Tecate beer, and you'll be set to graduate with culinary horizons appropriately expanded.