Hi, for those who don't know of this problem please see here:
http://www.subsim.com/radioroom/showthread.php?t=139151
There are 2 files, one for stock GWX 2.1 VIIC:
http://files.filefront.com/GWX+21+VI.../fileinfo.html
and one for Rubini's Water Stream mod that is based on the GWX 2.1 dat file:
http://files.filefront.com/Rubini+Wa.../fileinfo.html
Many thanks to SquareSteelBar for fixing the Stock VIIC version & Rubini for the fixed version of his Water Stream Mod, as well as Skwas for the use of his S3D utility.

Also many thanks to those testing the file, Koondawg, Badwolf & special thank to OLC & Anvart for pointing to the "WaterReflection" node that had the bug.

This is not an official bug fix as it has not been varified by BBW or any of the GWX team, Cheers.