Not sure if its compatible with the shaders you currently use....
http://stalker.filefront.com/file/Stalk ... ders;95346
The video does not show it off that well, check the screenshots posted in the comments, it makes the water far more transparent than any texture hack could... may be worth a test, I will do so myself as well.
Edit: Not that impressed to be honest, maybe its because I use an old Float32 shader package as well...
Anyway, on the APC and Heli topic, some good and bad news.....
I can get rid of the light bug when you kill an APC, but it is as I thought a side effect of the muzzle flash. I disabled the muzzle flash and killed three different APC's, no light bug. So I can fix it, but you lose muzzle flash when the APC fires, you still see the particle, but there is no light effect. Let me know what you think.... the file I would have to alter is w_mounted in the config/weapons folder.
I can reintegrate the "new" texture for the APC as it already used a different mesh..... but for the Heli, I have to create a new mesh, which I have done... bad news is it also requires some minor changes to the all.spawn for the new mesh to be used. I am pretty sure NEWSA scripted choppers would use my new mesh, but those defined in the all.spawn (vanilla choppers) would not, so it is not essential to alter the all.spawn.
Are you able to edit the all.spawn NW??
It is a very simple tweak, that should not mess with the game, basically finding every chopper, and changing the name of its mesh to my new one. By my reckoning that would be on the Escape, Darkvalley, Rostok, Yantar, Red Forest, Prypriat and Stancia 1 levels!!
New game required though

Edit 2: Just thought, because it is only changing one character in the name of the mesh, I don't even need to decompile the all.spawn, I can do it with a hex editor easily!! If you agree, send me the latest all.spawn for Newsa please buddy.
... and the w_mounted file if NEWSA uses that one already, and you want me to fix the light bug...