Hydroplane Racing Mecca Silenced

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Slo-mo-shun IV was a key player in Seattle’s powerboat racing scene.

Slo-mo-shun IV was a key player in Seattle’s powerboat racing scene.

While boat sales and boating are riding a solid wave in the Pacific Northwest, Seattle’s iconic hydroplane races didn’t leave the dock last weekend for the first time in 70 years, scuttled by the Covid-19 pandemic.

Still, the fascinating story of the boat that thrust Seattle onto the nation’s racing scene is still being celebrated this week, and the return of the annual Seafair festival is already slated for next summer.

It was 1950 when an Unlimited hydroplane named Slo-mo-shun IV fired up her 12-cylinder Allison fighter plane engine and roared around Lake Washington. Detroit at the time was the center of U.S. powerboat racing. That a hydroplane from Seattle could even hope to successfully compete, never mind dominate, in Detroit seemed a pipe dream. It wasn’t.

The story of Slo-mo-shun IV and her impact on Seattle and the powerboat racing scene is aptly told by Andrew Muntz in The Seattle Times’ current issue of Pacific NW Magazine. Muntz, who grew up in Seattle and watched the city become a big-time hydroplane center, is editor of Unlimited NewsJournal, the primary source of news about Unlimited hydroplane racing. He is also author of At the Ragged Edge, a biography of legendary powerboat racers Gar Wood and Bill Muncey.

“We were captivated by the boats,” Muntz says. “We stood awestruck if we saw one at a shopping center or on display at the boat show, and we loved watching them in action, throwing spray high into the air and making a thunderous roar that rattled windows three miles away.”

Three Seattleites — limited-class racers Stan Sayers and Ted Jones, along with master shipwright Anchor Jensen of Jensen Motor Boat Co. — developed and launched their Unlimited-class boat in late 1949 and began test runs on Lake Washington.

“The golden-brown craft with red trim attracted a great deal of attention during its test runs on Lake Washington,” says Muntz. “People wondered about its shape — somewhat like a flying saucer, 28 feet long and nearly 12 feet wide — but mostly they heard the thunderous noise of the Allison engine. They were also amazed by the plume of water that shot 30 feet into the air behind it — a rooster tail caused because the boat literally flew across the lake’s surface, and its propeller penetrated only halfway into the water.”

By June, 1950, Slo-mo-shun IV was ready to challenge the world’s straightaway speed record, set in 1939 at 141.74 mph. Slo-mo-shun hit 160.3235 mph, averaged for two runs. To prove it wasn’t a fluke, according to Muntz, Sayres drove the boat to a record of 178.497 mph two years later.

Detroit was always in Slo-mo-shun’s future. After all, the Motor City was the epicenter of powerboat racing, most notable for the Gold Cup on the Detroit River ever since Chris-Craft founder Christopher Columbus Smith built a boat that won the trophy in 1915.

As Muntz tells it, since the days of Smith, hydroplane bottoms had steps that allowed the boats to skip across the surface and run faster. Slo-mo-shun team member Ted Jones, a supervisor at Boeing aerospace, believed speeds could go a step further if the stern were out of the water, too. He and Sayres successfully tested the theory on another limited-class boat, then incorporated it in the building of the Unlimited hydroplane Slo-mo-Shun IV.

Detroit was now in their sights. But while Slo-Mo-Shun ran fast on straightaways, the question was whether she could navigate the buoyed turns on the racecourse. The rest, as they say, is history. Slo-mo-shun, now driven by Jones, easily was the fastest boat on the Detroit River and was crowned 1950 Gold Cup champion.

One might think the heroic return to Seattle of the Gold Cup-winning trio would be sweet enough. But there was a bigger prize for their hometown fans, such as Muntz, who had watched that hydroplane fly across Lake Washington. At the time, the Gold Cup winner could decide where the the next year’s race would be held. Yes, the 1951 Gold Cup was held on Lake Washington for the first time. Seattle soon became, and remains, the center of powerboat racing.

Writes Muntz: “That place in history, and the passion for boat racing in this corner of the nation, explains why the Slo-mo-Shun IV is a treasured artifact, displayed in Seattle’s Museum of History & Industry.”

“It not only stole the thunder of the world’s Motor City … it gave us a great reason to get outside every summer for a Seafair celebration that revolves around these flying boats,” museum director Leonard Garfield says.

There’s no doubt that thousands of people will line the shore to hear boating’s roar again next year.


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