After spending all of last week circling Hawaii's Big Island with its tail entangled in hundred of feet of fishing netting, a 40-ton humpback is now swimming free. During a rescue operation lasting several hours on Friday, experts with NOAA and the U.S. Coast Guard were able to cut the line away from the whale's tail.

The 45-foot long humpback was first spotted off Hawaii's Kona Coast on February 13, but the whale proved difficult to locate, delaying a rescue operation until the whale surfaced in safer waters. A rescue attempt was nixed last Monday when the whale moved into rough seas.

"We decided to stand down and be patient and wait for the weather," Ed Lyman, the marine mammal response manager for NOAA, told West Hawaii Today. "It's hard enough to be towed behind a whale in a calm sea. We had to be patient."

On Friday, with calmer seas and good weather in their favor, the rescuers trailed the whale in an inflatable as the marine mammal remained close to the ocean surface.

A special knife affixed to a pole was used to cut away the tangled netting piece by piece.

"We had to make three approaches, four cuts was enough for last wrap to get gear off her," Lyman told local news station KHON2. "We went by the back and went really well, very slow, very methodical."

HUMPBACK HEROES: Earlier this weekend, a team of specially trained @NOAA rescuers successfully freed a #humpback #whale from a life-threatening tangle of fishing gear off the #Kona Coast of #Hawaii! Led by staff from #HawaiianIslands #HumpbackWhale National Marine Sanctuary and @NOAAFisheries, the responders tracked the whale for more than a week before getting close enough to cut it free from at least five wraps of heavy gauge line around its tail fluke Friday afternoon. #Marinedebris is a major threat to the health of the world's whales, and NOAA works around the clock to protect the health of these majestic animals. (Photo: R. Finn/NOAA MMHSRP permit #932-1905) #EarthIsBlue #marinelife #whales #humpbackheroes #animalrescue #noaa #humpbacks A photo posted by US National Marine Sanctuaries (@noaasanctuaries) on Feb 22, 2015 at 12:13pm PST

The rescuers used a GoPro camera to peer below the ocean's surface and ensure they'd removed all the rope. Only a short piece was left, embedded in a wound in the whale's tail that experts said would likely heal and slough off.

The NOAA's search and rescue efforts were assisted by the U.S. Coast Guard, as well as the West Hawaii Marine Mammal Response Network, and several other local organizations.