FAQ Section has this info - sounds like you don't have the rudder locked into the down position to me - or they are raked back too far - need to tuck the rudders under the transom further.
Here are some links for you to read:
viewtopic.php?f=18&t=467viewtopic.php?f=18&t=12859Also the owner's manual might help explaining how to rig and sail the boat - big thing is getting the rig right and the rudders locked down (make sure your cams are functioning corectly)
link:
http://www.hobiecat.com/support/products/hobie-16/