Great questions.

There are many different topics on our forum related to the question about waterproof connectors. We do not have an official recommendation, but you can see what has worked for other people.

As for the tether management, I would encourage you to take a look at this Community Hack guide that was written.

Good luck with the remaining part of your build!

-Brian G.

I took the standard wire and put it inside three 100' lengths of 1/4-inch poly rope (available at ACE hardware for about $10 each). At each end, I connected the wire to "LEDJump 18AWG Wire Gauge Male Female Plug 2 Pin LED Waterproof Connector Cable Black (5-pack)" available through Amazon.com (priced at about $13 - only used three). I connected each rope separately with standard clips. The wired connectors are very strong but I use the cable to pull the teather and not use the wired connectors. My ROV uses one of these rater than the strain relief and wire in the standard directions. My poly rope attaches (clips) to the back hole of the ROV and the connector cable goes all the way to the wire harness and uses several zip ties as additional strain relief. My ROV is completely separated in the case from the cabling.