Hi Ron,
Rest assured the Velocitek Speedpuck is indeed legal and in fact used by many racers at the annual Ensign Class Association Nationals. The class, however, does not allow integrated electronic systems that perform calculations like VMG. Stand alone, compasses and speedometers are perfectly okay. A popular compass that is often used along with the Speedpuck is the Ray Marine Tack-Tick compass which reads your heading.
Best Wishes,
Pete Kogut
Past ECA Commodore