The 106th Chicago Yacht Club Race to Mackinac, the biggest and most varied sail regatta in the Great Lakes region, starts at 3 p.m. today.

About 320 boats will be racing this year. In a nod to social media, 13 have been selected to use GPS transponders to tweet during the race from @cycracetomackinac.

The 333-statute mile (289.4-nautical mile) race from Chicago starts just off Navy Pier and ends at Michigan’s Mackinac Island. First raced in 1898, the Mac is the oldest annual freshwater distance race in the world.

The standing record for fastest completion of the race by a monohull was set by Pyewacket, owned and skippered by Roy Disney. He set the record in 2002 with an elapsed time of 23 hours, 30 minutes and 34 seconds. For multihulls, the record of 18 hours, 50 minutes and 32 seconds was set in 1998 by Steve Fossett on Stars and Stripes, the catamaran that Dennis Conner previously sailed in the America’s Cup.

The race usually takes most of the fleet between 40 and 60 hours to finish.