Updated

DETROIT -- Boats and a helicopter searched northern Lake Michigan on Monday for two people who went missing when their sailboat capsized during the annual Chicago-to-Mackinac Island race, the Coast Guard said.

The crew of a competing boat, Sociable, notified the Coast Guard early Monday that the 35-foot sailboat, WingNuts, capsized near the Fox islands, west of Charlevoix, during the Chicago Yacht Club's annual Race to Mackinac, Petty Officer George Degener said. Charlevoix is about 270 miles northeast of Chicago, on the eastern coast of Lake Michigan.

The Sociable crew said eight people aboard WingNuts went into the water, and that they recovered six of them, according to the Coast Guard. All six of the people recovered were wearing life preservers, and they were taken to the Coast Guard station in Charlevoix for evaluation, the agency said.

Authorities did not release the names of the missing crew members. WingNuts is based in Saginaw, and seven of the eight crewmembers registered for the race are from Michigan, including three from Midland, two from Saginaw, and one each from Ann Arbor and Grandville, according to the race website. One of the crewmembers is from Chicago.

The Coast Guard located the overturned boat and was searching the surrounding area in boats and a helicopter

Thunderstorms had reportedly moved through the area overnight, and the air and water temperatures early Monday were in the low 70s, with 4- to 6-foot waves.

On their website, race organizers said the tracking system racers and fans use to follow the competition online failed, and that the Coast Guard was closely monitoring the fleet and reporting positional information to race officials.

Degener said the tracking system's failure did not hinder or delay rescue efforts, and the Coast Guard said in a news release that a private company that monitors locator beacons notified it that two beacons aboard WingNuts had been activated.

According to the race website, 355 boats and roughly 3,500 crew members took part in this year's race, which starts at Chicago's Navy Pier and finishes off of Mackinac Island, near where lakes Michigan and Huron meet. The first race was held in 1898, and organizers began holding it every year starting in 1921. This year's race is the 103rd running.