Compared with the distance it had already come, the little turtle’s voyage from Martha’s Vineyard to Woods Hole was short. The only unusual thing was, it went by ferry.

Shellbey, the juvenile Kemp’s Ridley Sea Turtle, was in bad shape, you see. Made lethargic by cold and battered by the weekend’s storm, it was washed up injured on the Island’s north shore.

It would almost certainly have died there and become food for the gulls, had Brendan O’Neill, executive director of the Vineyard Conservation Society, his wife Linsey Lee and their daughter Mya not gone for a beach walk on Monday afternoon.

“Brendan saw it first,” said Ms. Lee. “It was on its back. It had an injured front flipper and some damage to its shell and was just lying there, sort of flapping.

“He called us over and put us in charge of finding a warmer place for it, and he went racing up the hill to try to get in touch with Gus Ben David.

“Gus said it sounded like an Atlantic Ridley Sea Turtle, just like Brendan thought, which is very rare in these parts.”

Mr. Ben David’s advice was to take it home, warm it up and keep it under observation for 12 hours, and, if it lived, seek further help for it.

So the turtle spent the night in their kitchen. It was Mya who decided to call it Shellbey — a suitably androgynous name, given that it is almost impossible to tell a turtle’s sex without dissecting it.

“After 12 hours,” said Mr. O’Neill, “the animal was looking a little more perky, at least moving its head a bit, and that’s when Gus suggested it was time to trigger the rescue chain.”

And it is quite a chain.

It began with Mr. O’Neill putting Shellbey in a box and taking it from their home to the Wakeman Center, in Lambert’s Cove, where it was picked up by Dave Grunden, the shellfish warden and natural resources officer and point person for all strandings of marine creatures on the Island.

He in turn took it to the ferry, and it was picked up on the Woods Hole side by Bob Prescott, who is the director of the Mass Audubon Wellfleet Bay Wildlife Sanctuary and also the northeast sea turtle stranding coordinator.

From there, it went back to Wellfleet for measurement and an initial condition assessment, and then, with a number of other turtles, rescued in places other than the Vineyard, on to the New England Aquarium for further treatment and recuperation.

As of Wednesday, when Ms. Lee checked with the aquarium, the little turtle was doing much better and now was given an 85 per cent chance of survival.

Of her family’s Monday discovery she said: “It was a good end to the Thanksgiving weekend. We can be thankful for playing a small role in this endangered turtle’s hopeful survival.”

In return for his deliverance, Shellbey now will play a part in scientific efforts to learn more abut his species.

Ridley sea turtles are the smallest of all the marine turtles, growing to a length of about three feet and a weight of maybe 100 pounds. They are of particular interest in several ways.

For one thing, they nest en masse at only a few sites around the Gulf of Mexico. At the one major recorded nesting site, the beach at Rancho Nuevo, in Mexico’s Tamaulipas state, the females arrive in groups in summer, and lay their eggs in daylight, unlike other species.

Between World War II and the 1970s, their population crashed, primarily due to harvesting of the eggs, considered a delicacy. They also got caught in shrimp nets, and, like other turtles, are apt to mistake garbage, particularly plastic, for food.

They were declared endangered in 1970, though, and nesting numbers have increased since about 1985.

The adults hardly ever leave the Gulf, but young turtles like Shellbey — who was only about nine inches long and maybe two years old — wander in ways and for reasons which are yet not entirely clear.

What is clear is that this can be a risky adventure.

Said Mr. Prescott: “The fall stranding of sea turtles is an annual event. We’ve had 55 Ridleys so far this year. We average 68 Ridleys a year, and we expect this year to be a bit above average.”

For some reason, they turn up in considerable numbers in Nantucket Sound and Cape Cod Bay in the summer months, even though the water here is colder than turtles normally inhabit. The likelihood is that they ride up on the Gulf Stream, then come inshore seeking food.

“The people who study Ridley turtles are amazed by the number we have here in the summer, when the temperature doesn’t really fit their image of where these turtles should be,” he said.

“But there’s plenty here for them to eat, and they usually get out by the middle of September when the water begins to cool down. However, if they miss that cue, they’re in trouble.

“Turtles function best at 80 to 90 degrees, and as the temperature declines they slow down because they are ectothermic [cold blooded]. Then if the wind is too strong, they can’t swim against it and wash up.”

Almost all the strandings happen in Cape Cod Bay. It seems the young turtles get stuck in that natural cul-de-sac as they try to go move on.

“But it is very unusual to have one on the Vineyard. I can’t remember when we had one strand at this time of year,” Mr. Prescott said.

“Usually they have no trouble getting around the Vineyard and Nantucket. Once in a while we get a loggerhead or leatherback on the Vineyard, but to get a cold-stunned Ridley’s is very unusual.”

He suggested the big storm of last weekend was to blame.

“It was a pretty good blow — gusts of 45 — and I guess the turtle was in too close to shore and could not swim against it, maybe because of its damaged flipper.

“If those people hadn’t been there, it would have been dead. They don’t do well when exposed to 38 or 43 degree air temperature, which is what we had.”

The big question is where those young turtles go if they don’t get stranded on our beaches. Do they just head south down the coast again, or are they just part-way through an even longer odyssey?

Some have turned up as far away as Ireland, having ridden the Gulf stream right across the Atlantic.

Indeed, said Mr. Prescott, some scientists think that long journey could be just part of an even longer one taken by young Ridleys, “where they circumnavigate the Atlantic, up on the Gulf Stream, down by Africa, through the Caribbean and back to the Gulf of Mexico.”

“That would be an extraordinary journey for a young turtles,” he said.

Maybe Shellbey now will help unravel that mystery.

Mr. Prescott said one of two things would happen to the little turtle now.

“Either it could be sent south to Jeckyll Island, Georgia, to the Aquarium there for later release into the Atlantic, or it will stay at the New England Aquarium or University of New England and be released into Nantucket Sound, sometime in July.”

When Shellbey is released, it will be fitted with an internal tag, a metal flipper tag, and maybe, if it grows big enough over the winter, a satellite tag, making it possible to track.

“Hopefully if that happens, he will do a better job of navigating next time, a year older and wiser,” Mr. Prescott said.