Petty Officer 2nd Class David Pettit monitors communications from divers in the water during hard hat training in Honolulu Harbor from the pier at Coast Guard Base Honolulu July 30, 2015. All of the air lines and communications with the divers are monitored while they are in the water to ensure safety and identify any problems before they become serious. (U.S. Coast Guard photo by Chief Petty Officer Sara Mooers)