As mentioned before, all 16's have a hook in the stern area that runs from the chine to the outer stake.  This was essentially a built-in set of trim tabs and the design was patented by Jim Wynne.  The ideal being, that once the boat was planed off, this hook area would be above the wetted running surface of the hull. The original production Ski Sporter was limited to about 41 MPH with the earily power options available at the time.  53 MPH was considered  the top speed before running into handling problems due to the lack of adjustable trim and the traditional method of optimizing bow lift.    The secret to plus 60 speeds with this boat is to lighten up the engine, raise the X-dimention, and to apply very little trim to the drive.