What to use on hull to protect against blisters

[mf01]

...
So to prevent blistering don't wax below the waterline, keep the hull clean of scum, use a teflon type scrub sponge like you would use to clean dishes that have a non-stick surface to clean the hull while in the water and your good to all summer long. ...

So in general, should you not wax below the water line? I don't leave my boat in the water, but have been waxing what I can reach on the trailer.

[bobchris]

So in general, should you not wax below the water line? I don't leave my boat in the water, but have been waxing what I can reach on the trailer.

If you are trailering the boat then it really doesn't make much difference