Bring water to a boil; add shrimp, and cook 3 to 5 minutes. Drain well; rinse with cold water. Chill. Peel and devein shrimp. Chop half the shrimp. Chill chopped shrimp and remaining whole shrimp.
Beat cream cheese at medium speed of an electric mixer until light and fluffy. Add lemon juice, mayonnaise, seasoned salt, lemon-pepper seasoning, and Worcestershire sauce, and beat until smooth. Spread mixture into a 10-inch circle on a large serving platter. cover and chill at least 30 minutes.
Spread cocktail sauce evenly over cream cheese mixture. Layer chopped shrimp, Monterey Jack cheese, and remaining ingredients, except whole shrimp, over the cocktail sauce. Top with whole shrimp. Cover and chill thoroughly. Serve with assorted crackers.