Index: ps/trunk/binaries/data/mods/public/shaders/glsl/common/los_fragment.h
===================================================================
--- ps/trunk/binaries/data/mods/public/shaders/glsl/common/los_fragment.h
+++ ps/trunk/binaries/data/mods/public/shaders/glsl/common/los_fragment.h
@@ -12,7 +12,7 @@
 #if !IGNORE_LOS
 	float los = texture2D(losTex, v_los).r;
 	float threshold = 0.03;
-	return (los - threshold) / (1.0 - threshold);
+	return clamp(los - threshold, 0.0, 1.0) / (1.0 - threshold);
 #else
 	return 1.0;
 #endif
Index: ps/trunk/binaries/data/mods/public/shaders/glsl/water_high.fs
===================================================================
--- ps/trunk/binaries/data/mods/public/shaders/glsl/water_high.fs
+++ ps/trunk/binaries/data/mods/public/shaders/glsl/water_high.fs
@@ -271,6 +271,14 @@
 
 void main()
 {
+	float los = getLOS();
+	// We don't need to render a water fragment if it's invisible.
+	if (los < 0.001)
+	{
+		gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
+		return;
+	}
+
 #if USE_FANCY_EFFECTS
 	vec4 fancyeffects = texture2D(waterEffectsTex, gl_FragCoord.xy / screenSize);
 #else
@@ -306,5 +314,5 @@
 
 	color = applyFog(color);
 
-	gl_FragColor = vec4(applyDebugColor(color * getLOS(), 1.0, refrColor.a, 0.0), refrColor.a);
+	gl_FragColor = vec4(applyDebugColor(color * los, 1.0, refrColor.a, 0.0), refrColor.a);
 }