So, do they have to be waterproof, and if they arent, what happens?

only if you capsize.

Ideally they should be water resistant. any excess exposure to most speakers will lead to early failure. I've nver had a problem with any tower speaekrs being ruined due to water in the 4-5 years I've had tower speakers on my boats.

Look for speakers made with rubber and plastic as opposed to cardboard and foam.

At some point you should figure that they will get sprayed or rained on even if you are careful. So things made of wood or paper should be coated with some kind of protection.

Let's see: boats are almost always used near water.... <BR> <BR>Ever get into a water fight with a rival boat? <BR> <BR>Ever have a rival rider come cruising near by, and throw a sheet of water over the whole boat? <BR> <BR>Ever get caught in a rain? <BR> <BR>The speakers don't need to be "waterproof" but they do need to be moisture resistant. Audio purists may prefer the sound quality of a paper cone but the paper will simply absorb too much moisture. Cones made of a plastic material will give you much better longevity.