Independence Day brought to mind the world’s first combat submersible. Built in 1776 during the War of Independence, Bushnell’s Turtle submersible was used in an attack on HMS Eagle on September 6th 1776. Being a history buff I cannot bring myself to buy some of the myth surrounding this undoubtedly courageous endeavor; it cannot be described as a success. My skepticism has nothing to do with being a Brit, I promise. But there’s no disputing the Turtle’s place at the start of the line for Submarine and Swimmer Delivery Vehicle (SDV) development.