loud sqeeking

Last weekend me and my friends went rideing in some pritty deep water. After a full day of creek rideing, we went home and cleaned our quads like regular. Now it seems that there is an awful sqeeking sound comeing from the rear brake. What would be of caused this, the water? What can we do to fix/Prevent this? :(

your pads are probly shot or theres crud between the pads and rotor...take the caliper off and check the pads out..if there still material left clean em up with brake cleaner

Mgrath is right,, you probably had crud get between them and then next time you stepped on it got it stuck in the pads, and now the crud scraped the rotor.. :devil