I am aiming at a 150' of workable depth with this Rov so I bought this 200' section of cat6 cable.
(After some further testing the tether is going to have to be shorted to 150'.)
I wanted to be able to remove the tether form the Rov for ease of transport so I am going to try out these Ethernet Buccaneer Connectors made by Bulgin.
Again with ease of transport in mind this is the Tether Slip Ring Tether Reel I am Designing.