The alleged kingpin in what investigators called the largest narcotics distribution ring in and around Montauk, which raked in as much as $100,000 in three weeks last summer, will spend the next decade behind bars.In Suffolk County Criminal Court on Tuesday, Justice Timothy P. Mazzei sentenced Geraldo Vargas-Munoz, who is from Rincon, Puerto Rico, to 11 years in state prison and five years of post-release supervision. Described by the County District Attorney's office as "the largest purveyor" and "major trafficker" of cocaine and oxycodone in Montauk, he was facing 25 years to life.The D.A.'s office said Mr. Vargas-Munoz, known as Chelo, sold drugs out of the back kitchen door at Swallow East, where he worked as a chef, and also supplied others with narcotics to sell. During a five-month investigation that culminated in August with the arrest of 17 people, Mr. Vargas-Munoz sold 67 grams of cocaine to an undercover officer, William Nash, an assistance district attorney, said at his arraignment. Many of the defendants were from Puerto Rico and held seasonal jobs in Montauk restaurants.Mr. Vargas-Munoz's attorney, Andrew Heffernan of Central Islip, said his client would get credit for the nine months he has been held at the Suffolk County jail and will end up serving about 10 years before he is released.On Feb. 7, when, according to the D.A.'s office, he pleaded guilty to operating as a major drug trafficker, an A felony, Mr. Vargas-Munoz admitted that a minimum of $75,000 in cash floated through his hands as part of the activity. He forfeited about $25,000 in cash, which has been turned over to the federal Drug Enforcement Administration.Officials used court-authorized eavesdropping and electronic surveillance as well as undercover drug buys to make their case. Police arrested Mr. Vargas-Munoz after he dropped his co-defendant Elvin Silva-Ruiz at Kennedy Airport in Queens on Aug. 14. He had $20,000 in cash on him, they said, reportedly to resupply the organization with more drugs. The following morning, police executed search warrants, finding half a kilo of cocaine allegedly belonging to Mr. Vargas-Munoz and 200 grams of cocaine hidden in a compartment under the floor of another co-defendant's bed.Mr. Vargas-Munoz faced the most significant charges among the 17 who were arrested, but his attorney painted a different picture for the judge. Mr. Heffernan said his client first came to Montauk in 2012 to work as a seasonal chef, and that it was not until much later that he became involved in the drug trade. "He rented a room and drove a beat-up car," Mr. Heffernan said. He called his client "a good man who made a dreadful and terrible mistake.""He is very sincere and genuinely remorseful," he said.Asked if he wanted to say anything, Mr. Vargas-Munoz told the judge through a translator, "I’m sorry. I'm sorry for what I did. I'm really, really sorry."After the proceeding, Mr. Heffernan said, "He was not a hardened drug dealer by any stretch of the imagination." The defense attorney, who was retained by Mr. Vargas-Munoz's family and said none of them could make it to court on Tuesday, said he had little involvement with the criminal justice system before his arrest last August. "He is just a chef," Mr. Heffernan said, noting he had worked at a handful of Montauk eateries since 2012 — with the exception of one summer when he worked in North Dakota."Somebody back home in his hometown . . . got him to do this," he said. "They trusted him."Even with the sentencing of the man who oversaw the drug ring in Montauk, the investigation is continuing. Cases against several others listed in the 33-count indictment are still pending. Mr. Silva-Ruiz, another key component in the distribution organization, is due back in court on June 13. A warrant is still out of the arrest of Angel DeJesus-Rodriguez.Last month, William Crespo-Duran, one of the pivotal members of the drug ring, was sentenced to six years in prison on a top A felony drug possession charge. Antonio Ramirez-Gonzalez, who had been described by the D.A.'s office as the "gatekeeper of ill-gotten proceeds," got a three-to-nine-year prison sentence in March. Gilberto Quintana-Crespo, who had a role in securing packages containing the drugs, got one year in the county jail.There were nine others arrested, but not named in the indictment.