U.S. Coast Guard members from Station South Padre Island, Texas, stop Mexican nationals aboard a lancha after crews in Coast Guard aircraft spotted them fishing in U.S. territorial waters May 1, 2015. (U.S. Coast Guard photo by Petty Officer 1st Class Andrew Kendrick) The call often comes in the middle of the night to the U.S. Coast Guard station at South Padre Island, Texas, rousing service members from their bunks. A lancha, typically a slim,…