Eric Miller wrote:

Bret does have a point, after all, the lowest risk of damaging the polarizer
or the lens is to keep them in their boxes and in a safe deposit box
somewhere.

What he said! My point was don't be so paranoid. A good lens hood
will keep the dog from licking the lens. A skylight filter is pretty
much useless. You want to protect your lens, use a lens cap.

Having said that, I can see using a skylight filter if you were
shooting a NASCAR race with all the stuff blowing up off the track.
Also, a sandstorm or a hurricane might be other times that a filter
could save the glass from getting scratched, but I don't shoot much of
those either.

As for the light loss and image degradation from a skylight filter, it
is minimal at best. But you could introduce more flare by using one.
Forget the skylight filter.
Use the polaraizer as the protective filter if you must. At least it
serves a second function.