We have decided to to go with making a tether that consists of (buoyant) 1/4 inch hollow braid poly-rope. This was done in order to provide the wire tether with some amount of buoyancy as well as to provide a secure means of retrieving the OpenROV in the event of total system failure.
In addition to constructing the Rope/Wire Tether, we built an inexpensive, easy to build Tether Management System (cord reel).
We have provided the following links to the written accounts of the processes that we used to build our Tether and Management System.
Part 1- Covers the construction of the Rope/Wire Tether: Tether System Part 1.docx (3.2 MB)
Part 2 - Covers the construction of the Tether Management System: Tether Syetem Part 2.docx (2.7 MB)