In my experience, even a cheapo fender like this can prevent the skunk stripe...and allow one to ride without waterproof clothing when there's just splashy stuff on the ground but no splashy coming out of the sky.

For years, I wondered why people used fenders. Turns out that I'd either been in arid climates, where there's no splashy stuff on the ground, or semi-tropical climates, where there's always splashy stuff coming out of the sky. Now I get it!