Look on the Hobie cat web site under the support section http://www.hobiecat.com/support/index.html . Go to the TheMightyHobie18/18SX manual and it will tell you how to adjust this. There are also lots of threads in the forums about this as well.
Nick
Current Boat Looking for one
Previous Boats '84 H16 '82 H18 Magnum '74 Pearson 30 St. Louis, MO