I have now tested the new 4K box from Foxeer on land and not underwater and I am very satisfied with that.
Sow i have made a underwater Housing to Foxeer 4K BOX (video out,on/off,rec and mode,access from control panel)
I will test it under water when I get time.
I have tested it to 10 bar and no leak,enough for me
Do not know where to mount the 4K box on the bluerov2, sow i try front and rear, i use the original holes which is made on bluerov2.