Advantages of waxing?

[PG]

After hauling my boat of the lake where it was moored since June, I found a lot of scuzz caked on below the waterline. I scrubbed it off with ammonia and water and one of those kitchen scrubby things (except I couldn't get to the part of the hull resting on the trailer bunks or the centerboard, which will have to wait until I can careen the boat next summer).
I have read about people waxing their hulls. Is there a practical reason for doing this, or is it just a cosmetic means of having a shinier boat? Does the wax prevent the slime from building up, or make it easier to remove? Is there a recommended brand? Can I apply it easily while careening the boat at the beach on the lake without worrying about polluting the water?

[GreenLake]

I suspect, waxing is mainly useful to protect the hull above the waterline (or on the trailer). However, while it provdes a nice surface where water runs off, it does not replace antifouling for boats kept in the water for the season. Some people with bigger boats sometimes use certain grease preparations based on vaseline to provide some under-water protection. They are supposed to work where the underwater growth problem is limited.

[algonquin]

I have read about people waxing their hulls. Is there a practical reason for doing this, or is it just a cosmetic means of having a shinier boat?

Speed !!!! and the fish get a better view. Brad