Walt Walters “Designer” & Jim Wynne “Engineer”

Two Very Special Boats.

 A potted history of Wyn Mill and Thunderflash

In 1962 whilst designing offshore craft for major boat builder’s, Walt Walters with Jim Wynne over a 3 year partnership, were laying the foundation of a hull design that became the basis of most of their major designs together for such companies as Don Aronow’s Formula Marine, Donzi and Magnum….this boat was Wynne’s own craft a 17ft  2 cockpit sports boat called WYN MILL designed by Walt Walters.

                              THE RESTORED WYN MILL

WYN MILL was built as a one off and such was the design input from both men plus resulting performance with any engine size it soon became regarded as the “Lotus” chassis of the ocean.

In 1962 she won her class in the Miami – Nassau race and the Miami-Bimini Run. In 1963 Wynne and Walters teamed up with Don Aronow and built the 23 ft Formula based on the 17 ft Wyn Mill as in the picture below of Lord Lucans MIGRANT

Meanwhile in Britain Tommy Sopwith had been competing in both Class 1 and Class 3 offshore with Ray Hunt designed craft in 1963 / 64. He campaigned the Bertram 31 THUNDERSTREAK and a Hunt 14 LITTLESTREAK plus TRAMONTANA 2, all for Dick Wilkins “WATER RATS TEAM”….

                      THUNDERFLASH in the CORNISH 100

For the 1965 season Sopwith raced THUNDERFLASH  in Class 3  built by Souters to plans by Jim Wynne… She was identical in all respects to WYN MILL although the chine layout and bow were significantly different but still had the same distinctive barrel stern. Thunderflash was powered by a Volvo Penta Aquamatic 120, the design was going to be the basis of a production range built by Souter’s but the project never actually got off the ground.

                       THUNDERFLASH in the SOLENT 70

THUNDERFLASH like her American sister proved successful out of the box winning the Cornish 100 at an average 50 mph, the Solent 70 and was 1st in class in the Wills round the Island but was 2nd overall.

There were only 2 examples of this  “WW” designed 17 footer built and although there are variations in the  lines forward of the cockpit they are basically the same and both still survive, the restored Wyn Mill is in Norway and Thunderflash in GB.

The 17 footer is not to be confused with the 16ft Wyn Mill 2, which became the basis for the Formula Junior, Thunderbird and Donzi 16 boats (THUNDERBOX another Sopwith boat  was part of a 3 boat entry in the PARIS 6hrs which included WYN  MILL 2 and Don Shead’s identical craft ). The 16 is a development of the original 17 footer .. Wyn Mill 2 was designed as a circuit boat,  Wynne’s boat in the Paris 6 hrs finished 1st and won several trophies.


 THUNDERFLASH and her sister WYN MILL are therefore unique examples of  Walters / Wynne ground breaking hull design / engineering and are irreplaceable, the forerunners of such craft as Ghost Rider, GEE, Thunderbird, Maritime and others too numerous to mention.

Thunderflash has now been rescued from obscurity and will be the subject of a major rebuild over the winter. Her new owners are hoping to present her to the public late spring 2014 and she will be the first Class 3 offshore racer to join the ranks of the many Class 1and 2 boats which are now restored or undergoing restoration.