In the Pearl Islands of Panama we pulled up to one beach and went snorkeling around a submerged submarine. The tides vary so much in the Pacific that a couple of hours later, the sub was fully exposed. The weird thing is, it’s a submarine built for the U.S. civil war. What the..?!!
A guy named Julius H. Kroehl designed the Explorer submarine and built it in 1865 for the Union government. As the civil war wound down, the government decided not to buy it after all. So Kroehl disassembled it and brought it down to this area for pearl diving. Things went fine for a while, but the design used a compartment where the air pressure matched the water pressure. The sub was going down to over 100 feet, before anybody knew anything about decompression sickness (the bends). The divers were surfacing way too fast and started dying from an illness nobody could figure out.
Kroel keeled over in 1867 and other divers took over until most of them had died as well. In 1869 the sub was abandoned where it sits now, on San Telmo Island in Islas Perlas.
See the full story on Wikipedia: Sub Marine Explorer.