One of the earliest working submersibles (submarines) in existence the Sub Marine Explorer was designed by Kroehl and Ariel Patterson. Built and launched in 1865 the sub was capable of diving to depths of 100 feet and was able to control its position using a series of ballast and compressed air chambers in combination with a hand-powered propeller and rudder. Initially designed for use as a mine layer or salvage vessel during the Civil War, it was never utilized by the Navy. Instead it was constructed for use in gathering oysters for their pearls.
The sub was tested in Panama in June 1867 and working dives began in 1869. Crews worked for a week before succumbing to what is now believed to have been a diving sickness know as “The Bends”. Abandoned soon thereafter in a bay of Isla San Telmo, the sub was in a very deteriorated condition when documented in 2004.