Two boaters who were “in the right place, at the right time” helped Wednesday with the dramatic rescue of nine children and three adults whose boat capsized in Hog Island Channel, in an area known for dangerous currents.

A professional diver, Mike Margulis of Marion, and a sailing instructor, Martin Van Breems of Connecticut, were among the first on the scene.

Van Breems, who is the president of Norwalk-based Sound Sailing Center, had a crew of four students and two instructors aboard the 45-foot sailboat Disco Volante for navigational exercises.

At 4:40 p.m., the Coast Guard received a distress call from Van Breems regarding a 24-foot powerboat, a Four Winns “bowrider,” that had capsized near the mouth of the Cape Cod Canal.

Van Breems said the Disco Volante crew found the boat and began plucking people from the water.

“It’s a lucky thing that we were well suited to get those people back on a boat quickly and safely,” said Van Breems. “That was our contribution.”

Van Breems said his crew rigged a line to haul eight children and one adult out of the water and onto the Disco Valente, which then sailed the rescued to the Massachusetts Maritime Academy.

However, one child, an 8-year-old boy, remained trapped under the boat.

Margulis, who has had his diving license for 15 years, heard the distress call over his radio while on the water in Marion. Usually, Margulis suits up to inspect hulls for a variety of vessels. Wednesday marked the first time he was involved in a rescue.

After hearing the call, he headed toward the scene and was soon overtaken by a Marion Harbormaster boat. He followed in that boat’s wake.

“When I arrived, the Marion Harbormaster asked if I had dive gear ready,” recalled Margulis. “I said ‘yeah’ and he said ‘get your gear on and dive into the hull.’”

Above the surface, Margulis said rescuers dealt with 4 to 5 foot waves while his own boat became swamped and was eventually towed to shore. Below the waves, he swam through tangled debris, searching for the child.

“I found an individual in a life jacket trapped in the bow section of the boat, unresponsive. I just grabbed him and covered his head to keep him from hitting his head on debris,” said Margulis.

He surfaced and handed the child to waiting Marion and Wareham Harbormaster officials.

“A rescue boat came in pretty well synchronized, nothing was said, and they immediately began CPR,” he said.

According to Massachusetts Executive Office of Energy and Environmental Affairs Press Secretary Katie Gronendyke, Marion Assistant Harbormaster Adam Murphy performed CPR on the child until the boat reached Tempest Knob.

The child was first taken to Tobey Hospital in Wareham, and was airlifted to Boston Children’s Hospital. The other survivors had no serious injuries. Gronendyke said the capsized boat was registered in Onset and left out of Stonebridge Marina. Massachusetts Environmental Police are leading the investigation.

Officials have not released the victim’s identity, his current condition or the names of anyone else on board.

Wareham Director of Natural Resources Garry Buckminster, who was also on the scene, said conditions were treacherous during the rescue.

“The area is well known historically for the southwest wind and outgoing current,” said Buckminster. “It creates a perfect setting for unfavorable and dangerous conditions. By far, some of the worst in Buzzards Bay.”

During the rescue, rough seas hampered the emergency response.

“We really had to be selective on the placement of the patrol vessels due to the propellers and the people in the water,” said Buckminster.

He added that officials’ thoughts are with the victims and their families.

“We are hoping for the best possible outcome for the family and the victim,” he said.

Despite the poor conditions, Buckminster credited first responders for their response.

“I cannot say it enough on how professional our team, which includes all of the surrounding communities, especially the Massachusetts Environmental Police and Marion Harbormaster Department, responded,” he said.

In addition to the Wareham Natural Resources Department, the U.S. Coast Guard, Wareham Police, Wareham Emergency Medical Services, Onset Fire, Mattapoisett Fire and Rescue and the Marion Harbormaster assisted in the rescue and response.