I have been using a tether disconnect on my ROV for a while now and I have had no problems. I have gone a deep as 208 m. So I figured i would post the connector I have been using in case any one else wants to try it. It makes it WAY more convenient to carry your ROV around.
I put a drop of mineral oil in just to be sure, but when I did “depth test 2” I tested one dry and one with oil and they both stayed free of water. The larger size, which I tested at the same time, had a tiny bit of water in the ‘dry’ one.
The first one I use was from Lee’s electronics, a local electronics store, but they haven’t had them the last few times I was in.