newer video with the Airlock placed under a lake /watch?v=SEwT585_rj8 With the new pistons I started with a simple castle gate but quickly imagined something far greater. Mind the compression sickness as we pass from air to water and back again through the automated airlock. The most complicated part of the circuitry is three RS NOR latch’s. One for each door and one for the overhead water hopper. RS NOR latch’s have two outputs that can swap states, one always on the other always off, and they have two inputs, one to trigger each state. This is perfect for having a door stay open for as long as you like. The button on the water side could be placed under water by putting it at the end of a two block deep hole with a sign or ladder on one of the sides just inside the hole to stop water flowing in. Please comment if you would like any more information on any of the techniques used.