Unfortunately, this poster scan is too small to discern the details of these boards...but they run the gamut from a low-to-high railed minigun (#1), to a double-ender with a fin box at each end allowing the rider to choose their rail line by swapping the fin (#2), to a longer, moderate outline, low-to-high railer (#3), to a full on pig shape with low-to-high rails (#4), to the most conventional shape, a mini-gun with high-to-low rails (#5).
This all came out of Bob White's Wave Riding Vehicle shop in Virginia Beach.
The current Wave Riding Vehicle version of history has all but erased White's name from the books. Not sure what's up with that. No Bob White, no Wave Riding Vehicles, IMO.