Seaman Marcos Mancillas, a non-rate stationed aboard Coast Guard Cutter Clamp, replaces a light atop a navigational marker in the Houston Ship Channel near Kemah, Texas, on April 24, 2018. CGC Clamp, built in 1964, helps to service the more than 600 aids to navigation markers throughout the Houston Ship Channel and its surrounding waterways. (U.S. Coast Guard photo by Petty Officer 3rd Class Johanna Strickland/Released)