Seafair Milk Carton Derby is on Green Lake Saturday, July 14, in Seattle.

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Creative homemade vessels take to the water at Green Lake for the Seafair Milk Carton Derby on Saturday.

Up to 100 colorful boats built with milk cartons or jugs for flotation compete in races for youth, adults, military and commercial groups, and in showboat design awards for noncommercial entrants. It’s all in fun, sweetened with $10,000 in prizes for events throughout the day.

All boats run on human-power only — no engines or motors are allowed, and even sails must be for decoration only, not power. Flotation must rely completely on milk containers. Above the waterline, almost any material is permitted. The racing category is for boats designed for speed, using mostly simple designs. Open-category events are also races, primarily judged by design and creative use of milk containers. The Showboat award is for style and creativity only, for milk-carton vessels of any shape or design that can stay afloat.

Activities on shore and in the water start at 10 a.m. The Parade of Boats for Showboat Awards is at 12:30 p.m. Races continue until the Racing and Open Category Finals at 1:45 p.m., with the awards ceremony at 3 p.m. (all starting times approximate).

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Onshore festivities include food vendors, displays and exhibits by local businesses, and autograph and photo opportunities with the Seafair Clowns, Seafair Princesses and the Sea Gals. Family activities include toy hydroplane building and towing, a hula-hoop contest, and kids’ entertainment area with play space, inflatables, a Pacific Science Center activity and clowns.

It’s the 43rd year for this longtime local favorite event that draws thousands of fans, so expect driving delays and limited parking.

If you’re inspired to participate in the Milk Carton Derby next year, now’s a good time to start; experienced participants collect cartons year-round.

Seafair continues with a variety of community events leading up to the Torchlight Parade July 28 and the Hydroplane Races and Air Show Aug. 3-5.

Seafair Milk Carton Derby

Time: 10 a.m.-4 p.m. Saturday.

Location: Green Lake Park, 7201 E. Green Lake Drive N., Seattle. On-site parking limited. Metro Transit information: 206-553-3000 or

Cost: Free for spectators. Boat registration closed.

More information: 206-728-0123 or

Madeline McKenzie: 206-464-8245 or

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