Keen-eyed observers will spot something new in Charleston Harbor this weekend as almost 300 sailboats hit the water for Charleston Race Week.

296 -- Boats entered in Charleston Race Week

$2.5 million -- Economic impact of three-day event

2,000 -- Sailors competing this year

The fastest-growing class of boats in the largest keelboat regatta in the Western Hemisphere is the J/70, introduced just a year ago.

There are 56 boats registered in the class, making it the largest one-design class ever at Charleston Race Week, which dates to 1996.

Former College of Charleston sailor Cole Allsopp will skipper one of the J/70s this weekend, and says there’s no mystery as to why the new design has taken the sailing world by storm.

“It’s a great boat,” said Allsopp, a 2011 College of Charleston graduate from Annapolis, Md. “It encompasses the sporting aspect everyone is looking for, but it’s also easy to set up, to sail and to launch. Even if you are not sailing at the highest level, it goes upwind well, downwind well.

“A lot of other boats go for the super-sporty approach and sacrifice the ease to sail and set up. The J/70 doesn’t compromise.”

Allsopp and his crew of ex-Cougars mates — Zeke Horowitz, Sam Stokes and Brendan Healy — put the speedy 23-foot long boat through its paces at Key West in January, leading the class for a couple of days before finishing seventh out of 39 boats.

As sailors learn what makes the new boat go, differences in speed will lessen and tactics will matter more. A home-harbor advantage could help the former Cougars.

“We will be prepared to use our local knowledge to put our boat in the right spots on the race course, where we will be able to use the speed that we know we’ll have,” Horowitz told ScuttleButt Sailing News.

There will be about 2,000 competitors on the water for Charleston Race Week, which runs through Sunday. Some 160 volunteers will man the race courses, with another 100 or so volunteers on-shore. It all adds up to an event that pumped $2.5 million into the Lowcountry economy in 2011.

“It’s just a great event,” said Allsopp, who administers a junior sailing program in Annapolis. “We get great wind and the current in the harbor creates a huge tactical factor that has to be accounted for. And it’s really a well run regatta. I’ve sailed in it three or four times and always have a great time, in the social scene and in the sailing.”

Participation is up by about 15 percent over last year, officials say, with about 85 percent of the boats coming from out-of-state, including 12 foreign countries.

A partnership with Outside Television gave Charleston Race Week the chance to air 30-second commercials for the event for about eight weeks, reaching some eight million households.

“We’re really pleased to see how popular this regatta has become,” said event director Randy Draftz.

“It appears we’ll have more than 200 boats in Charleston Harbor, so it’s going to be an amazing sight from almost any perspective.”