Do you have a problem with spots on the window's of your boat?
I have found the way to clean the water spots off is to use SCRUBBING BUBBLES.
Spray the srubbing bubbles on and let them sit for a couple of seconds then wipe with a sponge till spots are gone then rinse well then dry with a squeegie(sp?) or a shammy.
when rinsing make sure you rinse all residue off of the window and your boat.