Updated

A 40-foot humpback whale wiggled off into the deep without a look back after ocean researchers and volunteers freed it from a tangle of abandoned fishing lines and other debris, possibly saving its life.

Whale watchers were looking for another dangerously entangled whale in waters around Hawaii on Wednesday, but experts warned against anyone trying to do the job themselves. Disentangling whales requires a special permit.

The rescue on Monday, using poles to untangle fishing lines and debris, occurred in waters off the island of Lanai, about 60 miles southeast of Honolulu, according to the National Oceanic and Atmospheric Association (NOAA).

The whale was tangled up in four different kinds of rope and three buoys. It was first spotted near the Big Island on Feb. 9 and then swam into rough waters, delaying the rescue.

"We believe it was exhausted. Dragging the gear was tiring it," said Edward Lyman, who worked with fellow whale sanctuary researcher Dave Mattila to cut the animal free.

For the first time, rescuers had attached a VHF tracking buoy to the whale so they could follow the mammal into calm waters.

The other missing humpback, with gear tightly embedded around the base of its tail, was considered to be in grave danger and was first sighted Jan. 29 off the Big Island by researchers from the Hawaiian Islands Humpback Whale National Marine Sanctuary, which helped free the first whale on Monday.

Divers and crew from NOAA and the Hawaii Department of Land and Natural Resources joined in the latest successful rescue, the first of the whale watching season in Hawaii waters.

A global volunteer group called the Whale Disentanglement Network, also was involved in Monday's rescue of the whale that had been dragging 25 feet of heavy fishing lines and other ocean debris from its mouth.

NOAA says whale entanglements in Hawaiian waters have increased in recent years.

Typically, large whales are able to scrape off the gear and swim away, but they are often hindered in feeding and may starve to death, researchers say.

Whale experts ask that amateur whalewatchers report entangled whales but advise that some seemingly odd whale behavior may not always be the result of an encounter with fishing lines.

They say mothers and calves often lie motionless at the surface just to rest, male humpbacks often breach the surface with a white spray that may appear to be debris, and some whales have 15-foot white pectoral fins that may be mistaken for fishnet.

The disentanglement network, which keeps special equipment for freeing whales, and has freed more than 50 large whales in recent years in waters along the U.S. and Canadian east and west coasts, the Caribbean and near Alaska and Hawaii.

David Schofield, a marine mammal response coordinator, said the whale freed Monday appeared to be fine.

"As far as turning around, they don't usually acknowledge the rescuers," he said. "They just kind of go on their way, which we are happy to see. It's a good sign to us when that happens."