This one man submarine I constructed out of a large piece of corrugated hdpe pipe and many other repurposed and recycled parts. Originally it took 4 months to build and then a month before it was tested and ready to dive. The final version had its own 3D drive system, almost a mile of wire, 4 motors, 4 batteries, 4 ballast tanks, numerous pumps, dials and an air compressor system along with many other features and safety equipment.