The Skeg system is quite simple. The skeg blade pivots down from the skeg housing. At the top of the housing the skeg cable exits through a plastic tubing that is attached to the underside of the deck. The skeg cable attaches to the skeg, runs through the tubing and ends at the steel rod found in the recess on the right side of the deck. The black control knob slides over the rod. The center of the control knob has a screw that penetrates the rod and the cable and allows you to raise and lower the skeg. (See diagram below)
If the skeg does not deploy freely, first check the housing for debris such as small pebbles or sticks. These objects can enter the housing when launching from a beach. If the skeg is really jammed, do not force the control knob. Use a wire or string through the pull hole in the end of the skeg to free it. If the skeg housing is clean, next check that the screw on the control knob is screwed into the cable. When you move the knob, the rod should move also. Then check that the cable tubing is secured in its connections at the skeg housing and recess. Those points have compression fittings. If the tubing is free of the fitting, reinsert the tubing by pushing it in firmly through the ring and seat it into the fitting.