By the numbers, they're 50 feet long and can reach top speeds of 50 knots — nearly 60 miles per hour — as they glide across the surface of San Francisco Bay.
But the numbers hardly speak to the experience of sailing on a vessel so fast that it goes twice the speed of the wind that's pushing it — or the experience of smashing into the surface of the water at that speed after making a slight miscalculation.
"It's not drenched, so much as the speed that the water hits you at. You're in a firehose," said St. Francis Yacht Club Commodore Paul Heineken, a former aeronautical engineer. "You can't see, and sometimes you have to hang on, so you don't get thrown off the boat."
Spectators will be able to witness the wild rides close-up this weekend as SailGP — short for Sailing Grand Prix — brings those boats within 20 meters of the shoreline for a series of 15- to 20-minute races featuring six national sailing teams.
Compared to the America's Cup in 2013, sailors say the races will be even more dynamic for spectators, since many will feature all six boats at once, and the boats are much faster.
"You get really caught up in a battle in the middle of the fleet," said Australian skipper Tom Slingsby, comparing the event to auto racing. "We don't want to be there, we want to be out in front at the first turn, sailing away."
SailGP will hold races on May 4th and 5th starting at 12:30 p.m. Spectators can watch from a free fan village near the yacht harbor adjacent to Crissy Field.