This is a little Sneak Peak of the new Rov I have been working on. It's really nothing that special, it's just a small (10" Cube) very basic (no bells or whistles) observation Rov. It is meant to be just something a beginner can build. I have been fully documenting the build along the way and writing up plans as I go. (writing the plans is a lot more work than I ever imagined it would be.) The idea was to offer these plans for sale on my website as a way to fund my site (Basically so it could pay for itself.) The main drive behind this was so I could move my site to server where I could have things like this forum (I couldn't do the forum from my service providers free webspace.) Anyway I haven't finished the plans yet and don't know when I will (I've been working on them on and off for over two years, yeah it was a lot more offs than on's) but I am working on them again after a long hiatus. Anyway I thought I would throw out a little sneak peak of it, it may not be paying for this forum but at least it can add some content
If I can chime in real quick I think what steve is using is polypropylene rope over the tether. The rope has to be the braided type not the twist type.
Paul's right, I am using hollow braid polypropylene rope. It acts as both a protective cover as well as a strength member of the tether. While the rope does float I will still have to add some type of floats to make the tether neutral buoyant.
As for the thrusters they are Johnson Mayfair Bilge pump replacement cartridges, they will be running a 50mm propeller. (not shown yet)