For those who have not yet pulled their boats: Recently in this forum I learned about "Slimy Grimy" for cleaning boat bottoms of algae and other crud. Pretty expensive stuff ($16.00 for one pound) but the product goes a long way and works as advertised and then some. Works best if you power wash first, then apply with a garden sprayer. My bottom looks like new! Thanks for the tip.http://www.slimygrimy.com/