With the frame complete and all the wires potted, it's finally time for a water test. Fortunately I don't have to risk any electronics for this test, instead just filling the sealed ROV with a few 1lb weights to keep it underwater.

Here's the ROV at the bottom of the bucket of water. The two domes - top and bottom - are bolted to the frame with their respective o-rings.

I left the ROV in the bucket for 24 hours to give any small leaks chance to show. I also included some leak indicating tape (https://smile.amazon.com/gp/product/B00MO2R7BC) around the lower dome. This tape turns red if *any* water touches it. If water made it inside, it would flow down over the tape making it very obvious where the leak was.

In the above picture, I've drawn around the indicator tape in blue (this is only a part of it of course). At the end there are no leaks! ... the first time that's every happened with my ROV builds.