In 2009, Britannic unexpectedly claimed a new victim when Mills’s friend and colleague, Carl Spencer, was killed during an exploratory dive. Mills’s account of Spencer’s last mission and the aftermath of his death is unbearably heartfelt. It offers an unvarnished glimpse into his own grief and anger.... Both a jeremiad of personal mourning and a tribute to his late friend, the section on the risks of diving to Britannic, even today, is harrowingly honest. Exploring the Britannic is a beautiful and often moving reflection on history, warfare, undersea exploration, friendship, courage and tragedy.