What is base sauce for shrimp cocktail Mexican style?

This is a good sauce, but there are many other versions: 1 cup water 1/3 cup lime juice 1 clove garlic, finely chopped 2 teaspoons salt 1 dash black pepper 24 shrimp, raw, peeled, deveined 1 avocado, peeled, chopped 2 jalapeno peppers, seeded, finely chopped 1/4 cup tomato, chopped 2 tablespoons onion, chopped 2 tablespoons carrot, finely chopped 2 tablespoons cilantro, fresh, snipped 2 tablespoons olive oil Juice of ½ lemon or lime 1 1/2 cups lettuce, shredded wedges of lemon or lime Heat water, lime juice, garlic, salt and pepper to boiling in a 4-quart dish; reduce heat and simmer uncovered until reduced to 2/3 cup. Add shrimp. Cover and simmer 3 minutes; don't overcook. Immediately remove shrimp from liquid with slotted spoon and refrigerate. Simmer liquid until reduced to 2 T; cool. Mix reduced liquid, shrimp and remaing ingredients except shredded lettuce and lime wedges in a glass or plastic bowl. Cover and refrigerate at least 1 hour. Just before serving place 1/4 cup lettuce on each of 6 serving dishes. Divide shrimp mixture among dishes. And garnish with lime or lemon wedges.