Early this week David Damroth was strolling Zack’s Cliffs in Aquinnah and gazed across the gulf to Noman’s Land when he saw an eruption from the water a mile and a half out. It was a double spout, a trademark of the critically endangered North Atlantic right whale. For the next 45 minutes he watched as at least three animals romped about the surface.

“They stayed in one place and you’d see their noses come out of the water,” Mr. Damroth said. “I have one photograph where the whale was almost lying on its back with its fins straight up in the air.”

With just over 400 right whales left in the Atlantic it was a remarkably rare scene.

“That’s just right whales being right whales,” said Michael Moore, a whale biologist with the Woods Hole Oceanographic Institution, hearing the description of the playful behavior.

Right whale activity, already of concern to federal regulators, is seeing redoubled interest in anticipation of wind turbine development in the waters south and west of the Vineyard. Apart from Mr. Damroth’s chance encounter with the whales, two ongoing aerial surveys have caught glimpses of the endangered animals in recent weeks. Since the fall, one survey — a joint project between the University of Rhode Island and the New England Aquarium and funded by the Massachusetts Clean Energy Center — has been patrolling an area south of the Vineyard recently designated by the federal Bureau of Ocean Energy Management for wind turbine development. In January the survey spotted two right whales several miles south of Long Point in West Tisbury on the south shore.

Tony LaCasse of the New England Aquarium said that area, though lacking data, is not considered a hot spot for right whales.

“We’ll see a group of a dozen whales or so on a very anomalous basis, maybe once every five years in the farthest western portion of the area,” he said.

A separate bird survey being conducted by the University of Rhode Island in the area between Aquinnah and Block Island, also eyed for wind turbine development, has made right whale sightings off Block Island. And on Sunday a group of three right whales were spotted in the approach to Naragansett Bay, just a day before Mr. Damroth’s sighting. Whether they were the same group of whales is unclear, but the sighting prompted a voluntary vessel speed restriction zone for mariners in the area.

The right whale, sometimes referred to as the urban whale for its near-shore comfort, and hunted nearly to extinction because of its docility, is especially vulnerable to human interaction.

“They’re a coastal whale,” said Mr. Moore. “If you look at the most recent mortalities in right whales in the last few years it’s been more of an entanglement problem than a vessel strike problem. They quite often feed at the surface and they also feed with their mouths open for a protracted length of time, so it’s a great way to catch any debris in the water. Wherever you’ve got fixed fishing gear, whether it’s trap fishery, like lobster traps, or gill net gear, those kinds of gear tend to be a problem. They can snag right whales very easily.”

He said the sighting between Noman’s and Squibnocket, if confirmed, is not totally unexpected for this time of year. Females that journey to the waters off Jacksonville, Fla., and Savannah, Ga., to calve are currently migrating back to Cape Cod Bay, the great south channel east of Nantucket and the Bay of Fundy to feed on the great blooms of planktonic crustaceans called copepods that blossom over the spring and summer. Mr. Moore admitted that whale activity has been slightly odd of late.

“They’ve been in Cape Cod Bay since before Christmas and they’ve been there in greater preponderance than they usually are, so it’s been an unusual year,” he said.

As for Mr. Damroth’s whales, Mr. Moore said the animals are given to bouts of playfulness between feeding, though the behavior could be less carefree.

“If the female doesn’t want to get impregnated she may roll on her back,” he said. “That doesn’t mean that the males can’t still do what they want to do, but they usually do a fair amount of foreplay.”

Mr. Moore will be making his own migration to the Vineyard this Saturday at the invitation of the Martha’s Vineyard Film Society. For Vineyarders whose appetite for all-things-whale rivals whales’ appetite for copepods, Mr. Moore will field cetacean-related questions after a 7:30 p.m. screening of the documentary The Whale at the Katharine Cornell Theatre.