A family of four was safely rescued from their boat near Sow and Pigs reef west of Cuttyhunk on Sunday afternoon, after a Mayday call signaled the boat was sinking, Coast Guard officials confirmed.

At roughly 3 p.m., the 47-foot sport fishing vessel was transiting at cruising speed through the reef when it struck a patch of rocks beneath the water and began to sink, according to Justin Longval, senior chief at Coast Guard station Menemsha. The boat, whose name was not confirmed by the Coast Guard, was likely returning from a fishing trip in the area, he said.

“[It’s an] extremely dangerous area, but at the same time an area that is well marked,” Chief Longval said, speaking to the Gazette by phone. “That happens a few times a year . . . I’m not going to say it’s super common but it’s definitely not uncommon.”

An unidentified civilian in a nearby boat responded to the scene, recovering two people from the water, Chief Longval said. All four passengers were transported to Woods Hole by the Massachusetts Environmental Police, he said. No significant injuries were reported to the Coast Guard.

Station Menemsha dispatched a 47-foot motor lifeboat in response to the incident, but the fishing boat’s passengers had already been safely evacuated prior to the arrival. The Coast Guard recovered floating debris in the surrounding water at the scene, including an EPIRB and a dinghy, Chief Longval said.

The extent of damage to the vessel could not be determined and the boat was too far below the surface to be towed, he also said. By early evening, the boat had all but entirely sunk, he said.

The exact cause of the incident was unknown and may be further investigated with the state, Chief Longval said.