As many as 90 sailboats are expected to race this weekend in the fourth annual Vineyard Cup. Last night Vineyard Haven harbor was full of visiting boats for the three days of racing.

This is the biggest summer event for Sail Martha’s Vineyard and the number of boats scheduled is up from last year. The style of boats participating is as varied as the sailors who sail them. Vineyard Haven outer harbor is now full of masts, booms and rigging. And the shore of Owen Park will be the staging area for many sailors.

“We’ve got one-design sailboats, schooners, gaff-rigged sailboats. We’ve got Nonsuch and every Friendship 40 on the East Coast,” said Brock Callen, program director for Sail Martha’s Vineyard. “We’ve got schooners with names like Juno, Charlotte and When and If.”

Vineyard Cup is a sailors’ regatta designed by sailors. Coincidentally, this is also the weekend of the Edgartown sailboat regatta. The Edgartown Yacht Club is hosting its 86th annual regatta. Even Menemsha Pond will be the site for fast sailing. Sail Martha’s Vineyard crews are running races Saturday and Sunday and they begin at 1 p.m.

Many boats will race down Vineyard Sound Saturday to a spot near Quick’s Hole, a passage between the Elizabeth Islands of Pasque and Nashawena. And they’ll race back. The sight is best seen from any beach on the Vineyard Haven outer harbor. The race begins at 10 a.m.

The best sail of all is Sunday, when the organizers put together a pursuit race. “Everybody has a different starting time based on a handicap,” Mr. Callen said. “The intent is to have all the boats finish together at about 3:30 to 4 p.m. Unlike any other sailboat on the race, a huge number of boats cross the finish line at the same time. The best viewing stand will be all along Eastville Beach. A handicap race allows sailors one of those rare opportunities to compare how well they are doing in relationship with other sailboats.

The Vineyard Cup is also a big event ashore. Owen Park is the designated meeting and refreshment center for the racers. During the morning it is where crew members gather before they go sailing and at night it is their place to party. The public is welcome to attend all weekend shore events with purchase of a $40 wristband.

Mr. Callen said the sponsors, Black Dog and the magazine Men’s Journal, are underwriting many of the weekend events.

“The big emphasis here is to have an affordable regatta,” Mr. Callen said. In the community of competitive sailing there are a lot of events up and down the coast that cost a considerable amount of money. “This is a regatta that is designed for the recreational family. Obviously safety is the most important priority. But we are also committed to fun and affordability,” Mr. Callen said. Sailors enrolled in the racing are spending as little as $50 for a boat less than 30 feet and as much as $125 for a boat in the 30-foot to 40-foot range.

Mr. Callen said he knows when Key West holds their race week, the registration cost is $850 for a 32-foot boat. That is not what Vineyard Cup is all about. Registration for sailors and their boats ended yesterday, but the event is still open for spectators and supporters.

“The emphasis for the public is join the party. Spend time with the sailors. Just be there,” said Mr. Callen.

Sail Martha’s Vineyard is a nonprofit organization committed to introducing Island children to the experience of sailing through free instruction. Much of the money that pays for programs comes from fund-raising. Last week there was a seafood buffet and auction. This weekend there is the weekend of racing.

“It is all about the kids,” said Mr. Callen. So much of the emphasis within the organization is about connecting youngsters to experienced sailors and the water. This weekend a lot of the youngest sailors in the program will have an opportunity to be on the water and watch and participate.

James Ulyatt, 13, of Edgartown, a student at the charter school, is a guest crew member aboard the 48-foot schooner Ishmael, captained by Fred Murphy. There are other young sailors on other vessels.

And there is plenty of competitive spirit in the adult racing. Phil Hale, president of the Martha’s Vineyard Shipyard, will be out on the water in his 26-foot sailboat Mischief, a Herreshoff design. Mr. Hale said that at last weekend’s seafood buffet fundraiser for Sail Martha’s Vineyard the conversations among sailors turned competitive.

Mr. Hale said he got the final word in when he predicted the winner. “If you want to get around the course, follow me,” he told his fellow sailors at the fundraiser.