While in the swimming underwater mode If you go on the top of the conduit and press F5 (Third-Person Mode) everything become Black.

Because The Video Is 186.29 Megabytes I can't add it in the attachments .
The Link : https://drive.google.com/open?id=1lxULkf1LAI44LTutz6YEVV6rlmzDJisw