What's the best way to clean heavy water spots on my hull?

[Lake Ape]

I have heavy water spots on my boats hull from the previous owner not wiping it down after using it and it looks bad, specially on the blue portions of the hull. The spots are really, really heavy but the hull is not oxidized. I tried a little bit of rubbing compound and that takes it off easily but I figure that isn't the best thing for the hull! My neighbor told me that soft scrub works really good and won't hurt it, another guy suggested something called Ducks? What does everyone use and are there any tips?
Thanks,
Lake Ape!

[Panic Button]

Vinegar straight will remove just about any water spots in seconds. Just remember to rewax the area.

[Angry Inch]

Like above, 1 part vinegar and 4 parts water. You may have to increase concentration for heavy spots. And, like Panic said, vinegar will strip wax. Good luck.

[tamalewagon]

PM Tobtek for some of his magic "sauce".

[h2oski2fast]

Shower Power, then a good wax job.

[phebus]

If they are really bad, you can use CLR. Wipe it on, and the spots come off immediately. Just be sure to wash the boat afterwards. Trust me, it doesn't hurt the gel, and was reccomended to me by one of the best detailers on the board.

[Mandelon]

Try a 22 oz framing hammer. :hammerhea :hammerhea
Vinegar is good stuff, CLR works too, but don't get it in your eyes...it hurtz!

[Tom Brown]

I have used toilet bowl cleaner and a toilet bowl brush (both new ). It works fantastic to get grime and such off of hulls. The hull will smell minty fresh afterward too.

[desertbird]

http://www2.***boat.com/forums/showthread.php?t=77682
Now, Ya'll aren't gonna believe this, but I swear it's true. :jawdrop:
Water is it's own best solvent. When I say that, this is what I mean:
For years I have had a spray bottle on the boat. Before we pull in to the dock, I fill it with whatever water I am floating on, be it Havasu, Mojave, The River in between or Castaic. Then when we pull out, spray down the water spots and they come off with a bath towel (provided you keep a good wax job)
No BULL! But there is a catch, and that is you must use the water you are on. Castaic water won't work on Havasu spots just like tap water wont work on rain spots. Believe it or not.
How did I come to this conclusion? Always owning a closed bow boat, and being anal about when we parked and having water spots while we float. A damp towel with lake water always did the trick, and I took it to the next level.
Save some $$$$ and use the Meguirs once you get home. This works great in between days on the weekender.

[Beer-30]

Desertbird, have you tried Plexus on your windshield yet? It made mine look absolutely brand-new.