Definitely take your pump off, take the back plate off, and have a look around in there, if you never have before. People usually recommend replacing the impeller yearly, although I can get away with waiting 2 years depending. Always always always have a spare impeller onboard for your raw water pump, it's an item that breaks often. Replacing it really isn't that hard, you just remove the two bolts that hold your raw water pump on, pull the pump off, detach the two hose clamps, and carry the pump over to a table and unscrew the screws. Take a look inside, see if any of the rubber impeller wings are cracked - if they are, you need a new impeller. Even if they're not, go ahead and order one or two spares, you'll need them eventually. Make sure the belt is tight when you put it back on.
I have to stand on my head to get down in there to remove mine, because of where it's located. Grr. Other than that, it's no big deal.
beej67, Checkered Past, 1980 32' Pearson 323, Panama City FL