Vandals have been targeting the boat house at the Sailing Camp Park in Oak Bluffs, leaving a trail of smashed-in doors, broken windows, floats set adrift in the Lagoon Pond — and, in a dangerous turn, the latest offense this week saw gasoline poured around the grounds.

At the receiving end of all this vandalism is Sail Martha’s Vineyard, the community-supported nonprofit program that leases the boathouse on the Lagoon from the town to teach sailing to Island children.

“You kind of wonder what’s going on here — why us, of all people? That’s the thing I can’t figure out,” said Sail MV program director Brock Callen yesterday.

“We can’t believe this is happening,” agreed Joan Hughes, who is chairman of the town conservation commission, which leases the property to the sailing program.

Mr. Callen said the program has never had a problem until last year, when small things began to happen. “We had a door kicked in, a porta-potty turned over . . . you know, you chalk it up to kids or teenagers, Mr. Callen said.

But this summer, he said, the vandalism began to escalate. A door was smashed. Floats that are used to tie up the sailboats were set free. Sailing program leaders responded by putting wire in the pins that hold the floats, but the vandals went to work and undid the extra wiring. Sailboats were taken for joyrides and returned with their seats smashed and broken. Rudders and tillers that belonged to the 420s were stolen. And last weekend matters escalated when someone broke into a locked shed that was used to store cans of gasoline. The vandals poured the gasoline all around and into the toilet bowl in a portable facility. An outdoor sink was left with its exposed plumbing twisted like a pretzel.

Mr. Callen, who has filed a report with the Oak Bluffs police and the town, estimates damages at $10,000 and counting, something Sail MV, which operates on a shoestring and fundraises to meet its annual operating budget, can hardly afford. He said a fleet of six 420s used by 14 summer sailing students, has been reduced to four.

“Now I have boats I can’t use in the summer program — when you are a program that does what we do for little or no cost, you certainly cannot afford to have this happen,” he said, adding: “Fundamentally, vandalism is jeopardizing what we are trying to do.”

Mrs. Hughes said the town plans to install a video surveillance monitor at the boathouse, which is in a remote location, down a path from the main building at the sailing camp.

“We’re not really sure what else to do — it’s a tough place for the police to patrol because it is way out of the way. But they [the vandals] haven’t touched the mainstay so they are really targeting Sail MV, and I can’t understand why anyone would do that,” she said.

Mr. Callen said his main reaction is disappointment.

“It’s more disappointing than anything else, to think that there are people out there that would do that to a nonprofit that is helping Island children. This is hurting the children, and our program has been hobbled by it,” he said.

And both Mr. Callen and Mrs. Hughes said the gasoline incident shook them.

“When they start messing with gasoline, that makes me nervous,” Mr. Callen said.

“That is what really scared me,” Mrs. Hughes agreed. “This has crossed the line and it’s serious.”