I bet remotely controlled submarines are really fun stuff as you can explore underwater world without getting wet. Jason’s built underwater ROV submarine is very original solution as its layout is based on PVC pipes.
It seems that design is still under strong development. Despite its first successful tests under water submarine will be upgraded to more flexible platform with things like leak detector, temperature and pressure sensors, air lift balloons, torpedo, sonar, grabbing arm, artificial horizon, compass, joystick control, AVI video recorder. All these add-ons will require a MCU to controls all bunch of sensors and parameters. But while project is in development, you can see current version of sub in action here. Let’s hope we will see finished version it.