ST. JOSEPH — Registration is open for the fourth annual “Rock the Boat” cardboard boat races, hosted by Whirlpool Corporation on Thursday, July 18 at The Inn at Harbor Shores, 800 Whitwam Dr., St. Joseph. Proceeds will benefit United Way of Southwest Michigan.

The life-size boats are made of cardboard, duct tape and polyurethane, and powered entirely by human paddling. The event is open to the public. The race begins at 5 p.m.

There are 75 boat slots available for registration. The registration fee is $250.

“This event has continued to grow every year, and that means more money to the community,” said Dave Cichocki, vice president of sales at Whirlpool Corporation. “We started with five boats in 2016, then 30 in 2017, and last year we had 64. This year, we’re capping it at 75 boats, so boaters need to register early.”

After registering a boat, participants will be provided with their own fundraising portal. The People’s Choice Award will be presented to the team that raises the most money leading up the race. The winner takes home the new People’s Choice Traveling Trophy and will present a $2,500 check to one of United Way’s funded partners of their choice.

To register a boat, sponsor the event or volunteer, visit uwsm.org/rocktheboat.