Niels Affourtit has put together a brilliant project, one of my personal ‘holy grails’ – a submersible drone controlled by a Raspberry Pi. He put the Pi together with some 3D printed parts, some sensors and an HD camera. According to a fan post on https://fpvfrenzy.com, the drone updates a web-page with the output from the sensors and is currently tethered with an Ethernet cable. You can see videos of the drone below: