Basic Underwater Demolition/SEAL students participate in surf passage at Naval Amphibious Base Coronado on January 21, 2014. Surf passage is one of many physically-demanding evolutions that is a part of the first phase of SEAL training. Navy SEALs are the maritime component of U.S. special forces and are trained to conduct a variety of operations from the sea, air and land. (U.S. Navy photo by Mass Communication Specialist 1st Class Michael Russell)