Homemade Diving Apparatus

Step 4 Air supply

In the first picture, you see a bicycle pump connected to the air hose to pressurize the helmet. If you use one, make sure it's a large one, capable of supplying enough air; an electric air compressor would probably work better and allow for longer dives. With my design, the diver must come up when the person working the pump gets tired. Probably, you could eliminate the topside air supply entirely and use a chemical re-oxygenation system inside the helmet itself, like on Isaac Peral - class submarines, and on the Columbiad projectile in Jules Verne's JOURNEY FROM THE EARTH TO THE MOON. If anyone knows how this could be done, feel free to comment!