Bob Conn was the man behind Conn-Craft and they were based in Miami, Florida. This boat company was already involved in flatbottom hulls and had two record setting hulls, Second Mortgage and Oh Mona Too in 1966. They also built an E-Service boat named Gentle Ben that was the 1972 National Champion.

The word is they used the wood International hull that campaigned as Black Magic to build the fiberglass plug for there first venture in hydroplanes. The first boat was Black Magic F-909 and was campaigned by Johnny White (owner/driver) starting in the spring of 1959. Jim Thompson has the Black Magic.

You can see one (or more) of these Conn-Craft fiberglass hydros running in the 1964 movie, Racing Fever.
Also, one (or more) of the hydros was reportedly used in the marathon-type races held in Florida during that era.

The fiberglass E/F class hulls were heavier than the wood hull and were not really competitive. Only 3 were made. Word is one of them burned to the waterline. Two are left. These E/F hulls were 17' 3" LOA with a 7' 5" beam.

After these smaller hydros were made, the plug was extended to pull J and H class hydros out. Perhaps the thought was the smaller 17' boats were too heavy for the E and F classes and maybe the big blocks would be better suited to moving the heavier fiberglass hulls (vs wood). This is the early 60s and fiberglass was just starting to become a viable boat building medium and probably alot of fiberglass and resin was laid up into these old hydro hulls. They do have fiberglass wood main stringers in them just like most boats of that era did. If you look closely at the larger hydros, it appears that the hulls were extended in the back as there is some extra real estate after the rear colwing and transom that you don't see on the E/F hydros..

The next batch of photos show Conn-Craft J and H class hydros running under 4 different names and 2 different classes.
All these are the same boat under different owners.