I am afraid I can give you very little advice on the use of a polarizing filter. First, while performing my duties as a whale watch naturalist, I typically was holding a camera body in one hand, as I was also cradling (and sometimes zooming) a lens in the other hand, as I was holding a microphone in my third hand, and as I was holding onto a rail with my fourth hand. Oops - I don't actually have that many hands (really). Well, as you can see, I certainly couldn't easily afford to be adjusting a polarizer very well (which would have also been complicated by the fact that my various long zoom lenses generally rotated the objective end of the lens when focusing -- if, on the other hand (so to speak), I could, when using a polarizer, somehow just "set it and forget it" - i.e, if the objective end did not rotate in use - it might have been more practical).
Besides, a polarizing filter cannot perform miracles -- it can help considerably with filtering out glare reflected off the water's surface, but it cannot help with the distortion of a target's shape and features due to refraction by a water-to-air interface that is all too often not "as smooth as glass", and it cannot help with water that is turbid (i.e., not "crystal clear"). Perhaps when watching whales near Hawaii, or in the Caribbean, where the water clearly (so to speak) seems nearly sterile (so that such places, therefore, do not represent major feeding grounds for typical large baleen whales), turbidity might not be a problem -- however, in many important feeding areas, where there is a lot of plankton in the water (supporting an active food web involving feeding by large baleen whales), the water is generally pretty cloudy, and a polarizer cannot help much with that. [Many baleen whales eat very little on their breeding grounds, doing most of their feeding for the entire year only on their feeding grounds.]
However, sometimes you do get LUCKY -- sometimes the target critter may be "trying to be photogenic" when the water just happens to be flat, and/or when the critter just happens to be in the shadow of the boat (where glare is naturally reduced), and/or when the critter just happens to be in the lea of the boat (where wave action may sometimes be reduced). But sometimes (well, most of the time) you just don't...
Here's a harbor seal pup that came up close to the surface right next to the boat in water that was relatively conducive for photography at the time --
However, 17 seconds later, the same pup had moved to where only his head, and little else of his body, was visible above the water --
Actually, when I've seen seals while on a whale watch, most of the time it was only the head that was visible, whether they were harbor seals --
- or gray seals (such as these traveling grays that briefly slowed down to do some "people watching" while our boat was stopped for us to watch some whales) --
Of course, sometimes what is going on above the surface is "the main event", an example of which is this gray seal "playing with" his din-din (an unlucky ocean pout) --
Whales (such as this "people watching" humpback) sometimes "spy hop", apparently to bring their eyes closer to (but usually still below) the surface, where they still have to deal with some of the same problems we photographers have to deal with --
But you are right -- most of the time "we will be able to photograph backs, tails, fins, blow holes, spy hopping, breeches and spouts etc, etc, etc, and so forth and so on as the whales break the surface of the water" -- most of the time we are left watching "the tip of the iceberg", such as with each of these three actively feeding humpbacks --
Here's a humpback seemingly doing some "people watching", likely checking out some distorted appearing little human critters while swimming in a circle (or, actually, an oval) around the boat, while the people are all looking back at the somewhat masked, somewhat distorted, and somewhat non-visible large friendly whale --
And the viewer's exact location may also be critical for successful viewing or shooting through the air-water interface as well -- here some whale watching passengers are obviously looking at whales swimming around the boat just below the surface, while - at least for me and my camera - the whales are nearly entirely masked by glare --
In Massachusetts Bay, the favorite food for most (but not all) species of whales is a fairly small fish known as American sand lance (nicknamed "sand eels", although they are not eels). Sometimes sand lance can be found partially buried in the sand at the bottom (hence their name), sometimes at intermediate depths, and sometimes even at the surface (where the wakes of their own motions add distortion to the surface, and where interface distortion can make them appear perhaps more eel-like than they really are) --
Sometimes, however, their appearance may benefit from more favorable conditions, making them a bit more "photogenic" --
But, they're even more visible when a surface feeding humpback whale makes a few of them "airborne" above the air-water interface -- |