There’s a powerful new tool that will likely be enlisted to help rescue entangled humpback whales and assist Hawaii researchers as soon as next year.

Aerial drones — those small, remotely piloted aircraft that are gaining in worldwide use — were given a thorough test run by a team of whale scientists and response managers during a two-week study in the waters off Maui last month.

“For me, it’s a tool with a lot of great possibility,” Ed Lyman, resource protection specialist for the Hawaiian Islands Humpback Whale National Marine Sanctuary, said Wednesday.

Three different types of drones were tested at the peak of the whale season to evaluate how they performed and whether the humpbacks would be bothered by the tiny and nimble aircraft.

Lyman, the man who has led the statewide response to entangled whales in Hawaii for more than 20 years, proclaimed the testing a success and said he’s hoping to deploy at least one drone starting with next year’s whale season.

While no entanglements occurred during the two-week study organized by the Office of National Marine Sanctuaries’ Collaborative Center for Unmanned Technology, the drones were used for plenty of up-close health assessments normally conducted from a distance while on a boat.

In addition, a drone captured rare video footage of a humpback whale doing what appears to be a headstand with its tail out of the water, as if catching the wind like a sail.

“Tail-sailing” is common among southern right whales but has been rarely documented among humpbacks — although there have been three reports of the phenomenon in Hawaii just this year and a few going back only six or eight years, Lyman said.

Lyman said it isn’t clear why whales do tail-sailing, but it could be a way for them to rest, nurse or just try to stay cool.

In any case, the detailed video footage demonstrates the power of the unmanned aircraft system (UAS) technology to elevate the level of both research and rescue operations.

Scientists describe the camera-equipped electric quadcopters as tiny and quiet, offering a safe, cost-effective and non-intrusive way to observe, document and even collect biological samples such as whale blow — the spray from its blowhole when it surfaces, a combination of mucus and cold air.

As for entanglements, the drones can hover above whales in distress and provide visual evidence about an animal’s condition as well as the best strategy for cutting it free from tangled fishing lines with a minimum of disturbance, Lyman said.

A waterproof drone can even land on the surface of the water and provide an underwater view of any problem or activity, he said.

As far as the whale is concerned, a floating drone is merely “an innocent piece of debris,” Lyman said. “That’s the beauty of this.”

During the study, a research team of 12, including a scientist with the Woods Hole Oceanographic Institution in Massachusetts, observed more than 15 humpbacks during more than a dozen flights with hand-launched drones aboard the sanctuary’s 38-foot research vessel, the Kohola.

None of the animals appeared to be suffering ill health, and none appeared to be bothered by the drones.

“We learned a lot,” Lyman said. “There was no hint of disturbance.”

More than half of the North Pacific humpback whales travel from Alaska to Hawaii each winter to give birth, breed and nurse their young in the relatively warm and shallow waters of the islands.

Sometimes these humpbacks get into trouble when, for example, they accidentally become entangled in fishing gear. Hawaii averages about eight whale entanglements per year, with 13 separate incidents recorded last year and five so far this year.

Lyman said 1 in 3 humpbacks have scars that indicate they are the victims of recent entanglements that have escaped on their own. It’s unknown how many whales are unable to free themselves and end up dying, he said.

There are regulations that restrict the approach to whales as well as public use of unmanned aerial equipment near wildlife. Last month’s exercise was conducted under permits issued by both the National Oceanic and Atmospheric Administration and the Federal Aviation Administration.

The study was part of NOAA Fisheries’ ongoing evaluation of unmanned aerials as it develops additional guidance for marine scientists.

According to the NOAA Fisheries Web page, some scientists and wildlife managers are concerned that drones could harm animals by disrupting migratory patterns, breeding, feeding and sheltering.

“As a result, NOAA Fisheries continues to evaluate both scientific research permit applications to ensure that the potential hazards do not outweigh the benefits, and other types of public activity that have the potential to negatively impact protected marine species,” the Web page says.

Michael Moore, a scientist at Woods Hole and a proponent of drones for whale research and response, called for continued assessment of the technology.

“Everyone from state and federal managers and regulators to the end users will need to continue working together to evaluate the efficacy and pursue the appropriate use of UAS platforms as extremely valuable tools,” he said in a statement.