Suffolk County police officers have searched every day during the past two weeks to find Gerson Salmon-Negron, a Queens man who went missing in the cold waters of Setauket Harbor following a plane crash — but have yet to find any sign of him.

Police dispatched again about 9 a.m. Saturday in their pursuit to locate the 23-year-old man, whose sister, Darcy Salmon, 39, of Manhattan, was simultaneously out searching nearby.

Salmon-Negron, of Elmhurst, was aboard a single-engine, four-seat Piper Archer plane returning to Republic Airport in East Farmingdale from a trip to Massachusetts when it crashed into the water just after 11 p.m. Feb. 20.

Three others were rescued from the wreck by Suffolk police Marine Bureau officers. A request for information on the crash was not returned Saturday by the National Transportation Safety Board, a federal agency that investigates aviation accidents.

In their tireless efforts, police have employed surface methods, side scan sonar — used to detect submerged objects in similar size to the victim — and underwater searches using police divers, Marine Bureau Lt. Raymond Epp said. Each day, two to three police officers are assigned to a boat that searches the shoreline and three harbors at Port Jefferson, Setauket and Conscious Bay during daylight hours. Police aviation units also scan the waters.

Seasonal weather patterns, including strong winds, tides and frigid air and water temperatures, have at times dampened their efforts, Epp said.

Slack currents have restricted divers in certain areas, while waves disrupt underwater visibility and the effectiveness of the sonar. Setauket Harbor’s tide changes by 8 feet every 6 1⁄2 hours, creating a “substantial” current, funneling the water in and out of a narrow inlet several times each day, Epp said. In addition, the three ferries that run from Port Jefferson to Bridgeport, Connecticut, which make numerous daily trips, result in a considerable amount of water displacement, leading to sizable underwater movement.

These factors have created the possibility that Salmon-Negron’s body has made it out to the Long Island Sound, which Epp says is checked every day as well.

Not yet recovering Salmon-Negron may be largely in part due to the water temperature, Epp said, which could cause his body to remain underwater until April, when warmer waters would help him resurface.

Still, Salmon-Negron’s family and friends are determined, strengthening their hope as the days go by, said Alejandro LaTorre, a friend and fraternity brother who has been organizing civilian searches. Last Saturday, Salmon-Negron’s mother, Ivette Salmon, and her daughter were joined by dozens of friends and other family members from across the New York metropolitan area to search for him. Their four-hour trek was spent walking miles of mostly rocky beach.

“I know that he’s dead, but I just want him back,” his mother said during the search Feb. 27. “We can’t stop looking.”

LaTorre said a large group is expected to return to the cove Sunday at 2 p.m. to look again during low tide.

Family members have said they want to recover his body for closure and asked the police and those living in the area to not stop looking. Salmon-Negron, who was set to graduate with a degree in business administration from the City University of New York, would have celebrated his 24th birthday on March 17, LaTorre has said.

“Quite honestly, this past week has been just trying to deal with the whole idea, trying to get an understanding that he is gone,” LaTorre said Saturday. “We have so many questions right now about what happened, but we just prioritize about finding him as soon as possible.”