Wet air filter is scary. you cant compress fluid so if you get it into your engine you can potentially do some major damage. A snorkel is ideal but i just bend my intake boot up to my cowling. The fan hitting the water can also do damage to the fan itself as well as the rad. If the blades on the fan get bent it can damage the rad. Best thing to do is get an electric fan with a kill switch so you can shut it off before you get into the water. water is ok in your drum brakes but if you get mud in them it acts as a polishing compound and wears them down quickly.
I'm sure others will chime in but thats all i can think for now.
Oh yeah, and have fun. <img src="/forums/images/graemlins/smile.gif" alt="" />