Polarizing filter and reflection on the water
I this experiment I was trying to study how much polarizing filter does impact reflection on the water. These 2 images are taken seconds from each other, both with circular polarizer attached but I turned the filter between the shots. Results seems to be quite clear here.
In this first one you can clearly see thru the water. Effect of polarizer is used to reduce the reflection as much as possible. And in the second one only reflections are visible: