The state medical examiner has determined that a Gloucester eel boat captain who died during an ill-fated rescue off Cape Ann late last year had drowned, a finding that brings new scrutiny to the equipment aboard the Coast Guard’s vessels.

David “Heavy D’’ Sutherland died moments after his 51-foot wooden boat, the Orin C, sank while under tow by the Coast Guard about 12 miles off Cape Ann on Dec. 3. The Coast Guard is investigating why the tow went awry and whether rescue vessels should be outfitted with more medical equipment.

Drowning victims can sometimes be saved if they’re underwater for only a few minutes and receive oxygen immediately, according to emergency medicine experts. But Sutherland didn’t receive oxygen because, unlike ambulances and airplanes, most Coast Guard vessels don’t carry it and crews aren’t trained to administer it, a Coast Guard official said.

“He should have had oxygen,’’ said Dr. Jarone Lee, an emergency medicine and trauma critical care physician at Massachusetts General Hospital. “Oxygen is a problem for drowning no matter what. So immediately, if you have access to oxygen, you should put him on oxygen.’’

Wearing a survival suit, Sutherland was in the 49-degree water fewer than three minutes before a rescue swimmer hauled him out of the 12-foot seas, according to Robert Lepere, who was at the time commanding officer at Coast Guard Station Gloucester. When he landed on the deck, he was not breathing and had no pulse.

Coast Guard crew members reported no signs of drowning, such as water in the lungs or foaming at the mouth, according to Commander Brad Kelly, who coordinated the Orin C rescue mission.

Crew members treated the situation as they would a heart attack, Kelly said. He said they would not have done anything differently if they had identified drowning at the time as a cause for Sutherland’s nonbeating heart. Given their training and equipment, the crew did all they could, he said.

“I don’t know that there was anything else to be done,’’ Kelly said. “They performed CPR as it’s laid out by the Red Cross.’’

Orin C crewman Travis Lane said he was surprised at the “drowning’’ classification.

“He made two strokes toward the boat and stopped,’’ Lane said. “You’re not going to drown in . . . 10 seconds or three seconds.’’

Sutherland’s death capped a series of problems in a rare rescue gone wrong. After a successful two-day fishing trip, the Orin C lost power, then probably sustained hull damage in a mismanaged tow from another commercial boat. The Coast Guard took over the tow some 18 miles off Cape Ann and ultimately rescued two crewmen, but could not save either the wooden boat or the captain.

The medical examiner’s finding raises the question of whether Coast Guard patrol vessels should be outfitted with oxygen and trained personnel who can deliver it. Currently, the only Coast Guard vessels with oxygen on board are those longer than 210 feet and designated for long-term deployments, not rescue missions.

The Coast Guard’s Orin C investigation is already exploring whether other standard equipment upgrades are needed. One focus: pumps for dewatering a sinking vessel. The Orin C sank after its crew had no success operating a pump from the Coast Guard.

New standards for pumps could potentially be one outcome of the investigation, said a spokeswoman, Lieutenant Karen Love Kutkiewicz.

In addition, the Coast Guard is weighing whether to make defibrillators mandatory equipment on all vessels. The Coast Guard crew wanted to use a defibrillator to restore Sutherland’s heartbeat, but Coast Guard vessels aren’t equipped with them.

A helicopter dispatched from Cape Cod tried to deliver one, but by then Sutherland had been unresponsive for about an hour and stormy conditions proved too dangerous to complete the operation.

Some experts say carrying oxygen on every vessel would be both feasible and important for saving lives since it’s always useful in a drowning situation.

“Having pure oxygen going into lungs, whether they’ve got some water in them or no water in them, you’ll get more oxygen molecules into the circulation,’’ said Dr. John Higgins, a sports cardiologist at McGovern Medical School at The University of Texas Health Science Center at Houston. “That could definitely improve the outcome.’’

The Coast Guard report on the Orin C is due as soon as next month. A report from the National Transportation Safety Board is expected later.

G. Jeffrey MacDonald can be reached at g.jeffrey.macdonald @gmail.com.