These engines are what this page is about:

Please visit this video to the great  series produced by Daryl Canada on You tube. Daryl explores, multi-tube engines, multi engines boats, diaphragm and other types. He stretches the boundaries on what can be done with lightweight sheet aluminum and imaginative uses for many found and re-purposed objects. 

Enjoy Daryl's great narration and exquisite boats in his unique testing tank. Go to Youtube and enjoy the whole series