The big wing nut...
Unless somebody has made an after-market modification, the tensioning clamp is the big wing nut (about 5" long) on the side (starboard) of the upper rudder housing. Tightening or releasing the nut moves the two large aluminum plates in which the swing rudder pivots. The nut should be tightened firmly when the boat is moored or when the rudder is up for trailering. The nut should be loosened to a moderately tensioned position when sailing to allow the rudder to swing back if it strikes the bottom or some other obstacle in the water, but not so loose as to allow the rudder to swing back from wave action. Similarly, the rudder line should be snugged to the cleat on the tiller during the occasions when the wing nut is tightened, and removed from the cleat while you are sailing, again to allow the rudder to swing when an object is struck. When sailing, the aft, upper, sloping part of the rudder (above the thinner blade part) should be exactly parallel with the the back of the aft edge of the aluminum plates that form the sides of the rudder housing. Helm will be adversely affected if the rudder is higher or lower than this parallel position. Hope this helps.Dale Wiles/v GrandechildSandpoint, Idaho