Your comments about polarized sunglasses are correct, additionally, polarized sunglasses can be a serious hazard when flying floats. However I think that you are a bit off in your condemnation of Serengeti sunnglasses. Corning does make some polarized lenses under the serengeti name, but all the ones that I have seen advertised for aviaton use, including in Sporty's, use the "drivers" lens. I don't believe that the "drivers" lenses are polarized. Thake a look at these links which contian descriptions of the various serengeti lenses.
I don't know know what I have on in my avitar (LOL). But I have Bolle Just because they block all UV rays. They are non polarized, some of the polarized glasses react funny with the elements of the windshield and can cause a rainbow effect with blind spots.