“Fish. Party. Repeat.” Those words, printed on a sign in a South Padre Island, Texas, restaurant, refer to two of the most popular pastimes there. SPI (as locals call it) and nearby Port Isabel also boast a long and inviting list of other things to see and do. It didn’t take long after my wife, Fyllis, and I arrived to understand that this is a place of outstanding beaches, numerous land and water activities, and intriguing historical tidbits. This is all well known to “winter Texans.” They are the people, primarily from the Midwest, who spend several winter months soaking up the sun and fun in those twin towns nestled along the Gulf of Mexico at the Lone Star State’s southern extremity. At first glance the two communities present the atmosphere of many beachfront locations. Hotels, restaurants and souvenir shops abound. Colorful golf carts are a popular mode of transportation, …