One of the critical parts of the boat is the hatch. It can be opened in order to access the electronics and it has to be perfectly watertight. The hatch in the pictures, which is normally used on yachts, has been mounted on acrylic “aquarium” for testing. It was left underwater for 7 days and there was not a single drop of water inside the aquarium.
Testing the hatch underwater
However, things get funny when the air trapped inside the hull expands during hot days and contracts when it cools down at night. Furthermore, if we want to use water pumps to get water out of the hull in case of emergency, the same volume of air must get in somehow. How to let the air in while preventing the water from entering the hull? There’s a really interesting device called a Gore membrane vent. It’s from the same material as outdoor Gore-Tex shoes. It’s surprising that you can blow air through the vent, but it doesn’t let any water in even under continuous pressure. The Gore vent fitted on the hatch has been tested underwater for a week, and again, no drops inside.
The Gore membrane vent mounted on the hatch for pressure equalization