I will wait to see the great white whale. (There is a white humpback in the Pacific.) But here is what I was thinking. On a sunny day, the North Atlantic is blue and the whales are mostly dark gray, would a blue filter make the water lighter and the whales more distinct? Should I look for a polarizing filter to deal with glare off the water? This all assumes that I actually snap the picture quickly enough. I always get a bunch of whale footprints, slightly disturbed water where the whale once was.