Circular Polariser

I went to Thrigby Hall a few weeks ago, and inside, they have a swamp house where they have crocodiles. I thought this threw up the perfect opportunity to demonstrate how a circular polariser works. The first image is without the filter on the front. The second image is exactly the same, same conditions, taken just after the first, but with the polariser on full effect. I love filters, I use my polariser and ND Grad filters quite a bit, it's always great when they pay off too. People quite often revert to Photoshop to add effects, I'd love to see someone replicate the effect a polariser can on reflections in water!