I've currently been doing FPV drone flights for about 2 and a half years and been a ROV pilot for about 10, I own a Blue ROV 2 which is great but also weights 10Kg and needs a laptop and someone tending tether to operate efficiently which can be bulky and bothersome.

The aim of this project is to have a underwater capable drone that can be controlled via my Taranis transmitter and view video via my Fatshark goggles. 

Radio signals and water have a fairly bad relationship so the first part of my project is to see about building a watertight drone with its signals back to the surface with an umbilical to the surface, to see how effective it is; whether I can get away with having the signal receiver and video transmitter on the vehicle then having the signals back to surface, or whether the signal receiver and video transmitter can be on a "Buoy" and signals can be sent up an umbilical. 

First things first, going to use some Cat5 and connect the drone at a distance of 10m and see if that effects signal and / or video.