Cmdr. John J. Christensen (left) exchanges a salute with Captain Ted M. St. Pierre, while Cmdr. Alan B. McCabe (right) watches on during the change of command ceremony, Thursday, May 24, 2018, in Boston (U.S. Coast Guard photo by Petty Officer 2nd Class Lara Davis) BOSTON — Coast Guard Cmdr. John Christensen relieved Cmdr. Alan McCabe as the commanding officer of Coast Guard Cutter Seneca Thursday...