If I use your level, the code works, but if I try to use your code in any other level, Wed crashs and it doesn't give any information.
The steps that I did to use your code:
* Make a new level.
* Open Map Properties and set the script to water_shader.wdl.
* Put water model inside and give it the water action.
* Run the level and Wed crashs.


OBS.: The engine is crashing, not Wed. Sorry!