After four decades of DIY submarine building, with his latest try being his eighth effort, Hank Pronk from Ainsworth in Canada has built the deepest-rated homemade submarine.

Called the Elementary 3000 (or E3000 for short), he pushed the boundaries of homemade design with a submarine rated to 3,000 feet/914 meters.

The depth rating is not just a theoretical calculation. Instead, the submarine was pressure tested in a pressure chamber in Vancouver to a depth of 2,900ft/883m, says Sam Helmy for Deeper Blue.

Take a tour of Pronk’s sub.