Like most visitors to Martha’s Vineyard Chowder Company, Buster the black Labrador was hungry for a snack when he bounded through the doors Wednesday afternoon. But instead of ordering at the bar, Buster earned his treats by showing off the skills for which he’s been trained: sniffing out a small bag of marijuana, intentionally hidden in a curtain at the restaurant. The year-old dog planted himself on the floor by the curtain, placed his nose on the drugs and received treats from his handler, Oak Bluffs police officer Jeffrey Trudel.

Buster, the hungry dog with a keen nose, is also the newest member of the Martha’s Vineyard Law Enforcement Council, where he and Officer Trudel will use Buster’s skills to assist agencies across the Island in detecting drugs and searching for lost and missing people.

The new canine unit was funded by donations, including $65,000 from Ernie Boch Jr., president and chief executive officer of Subaru New England and a homeowner in Edgartown. Funding went toward instruction­­ — Buster completed formal narcotics training and human air scenting training­­ — and equipment. The department also received donations for dog food and veterinary care, which made it possible for the department to add Buster at no cost to the town, said Oak Bluffs police chief Erik Blake.

“I’m honored to even be a part of this,” said Mr. Boch, who said he’s been coming to the Vineyard since 1966. “I just love this Island. Anything I can do to supply what the Island needs.”

A crowd of law enforcement members and others dined on chowder and meatballs provided by the Chowder Company Wednesday and were entertained by Buster’s drug-detecting demonstration. When Officer Trudel slips a special orange collar over the dog’s neck, he said, the dog is told to go on the hunt. He’s been trained to detect at least .25 grams of marijuana, cocaine, heroin, methamphetamine, ecstasy, Oxycontin and Suboxone, and “he just started on Percocet,” Mr. Trudel said. Buster also received training for tracking human air scents, which can be used for search and rescue operations.

Buster is considered a passive, rather than aggressive, search dog. The latter will bark, scratch or bite when they find a scent, potentially causing property damage, while Buster lies or sits by the source, putting his nose on his find to receive food.

Buster eats only from Officer Trudel’s hand, making him eager for the morsels the officer doled out from a black pouch on his belt.

The dog’s skills will be made available for use Island-wide, including going to the airport and ferry terminals and sniffing luggage. His discoveries are admissible in court, Mr. Trudel said, as long as his training records are kept up. “In his nature, he doesn’t lie,” his handler said.

Buster already has been called out to the job, said Oak Bluffs police Lieut. Tim Williamson, with Buster executing a few search warrants at motor vehicle stops. On a recent search, he said, Buster detected just the scent of marijuana in an empty Ragu spaghetti jar, and can also detect a pill and a half of Suboxone.

Just having the dog serves as a deterrent, said Mr. Williamson.

People might be dissuaded from bringing drugs to the Island by “the mere fact that people know there’s a drug-sniffing canine,” he said. “I would imagine it’s going to have an effect.”

Mr. Williamson and others said that Buster also addresses a growing drug problem on the Vineyard. “There is a big problem,” Mr. Williamson added, with pills and pharmaceuticals “easy to hide,” and drugs like Suboxone highly abused.

The canine unit presents a “big toolbox of resources,” said Chief Blake. “I really like the tracking part,” he added, noting that the dog can detect not just missing children, but missing Alzheimer’s patients.

“To have him here on the Island, to respond immediately, is a great asset to have,” Officer Trudel said.

While officials tout Buster’s service to the Island, he’s also been a welcome addition to Officer Trudel’s home. Buster lives with the family in Oak Bluffs, joining other dogs, cats, horses and chickens. At home, he’s just a dog. “He’s a smart Lab 15 minutes of the day,” he said.

Family walks even play a role in Buster’s training. During one stroll with Mr. Trudel and son Taylor, nine, Buster noticed that Taylor had wandered away and went to find him. Hide and seek is similar to search-and-rescue training — and Taylor is now a frequent target for Buster’s training searches.

Having Buster around is “really fun,” Taylor said.