Construction Mechanic Constructionman Luis Perea assigned to Beachmaster Unit One (BMU-1) teaches fellow unit members how to calculate a Modified Surf Index (MSI) and take wind readings during a quarterly beach exercise on Dec. 9, 2017, on Naval Amphibious Base Coronado. Beachmaster Unit One deploys and supports combat ready Beach Party Teams in support of amphibious operations around the world. (U.S. Navy Combat Camera photo by Yeoman 1st Class Anthony Ardisone)

Photo by: Petty Officer 1st Class Anthony  |  VIRIN: 171209-N-HW735-1374.jpg