Federal marine officials freed a young humpback whale from a tangled web of rope Sunday in waters west of Moloka'i.

The yearling was first spotted Dec. 1 by the crew of the Pacific Whale Foundation's Ocean Explorer entangled in polypropylene rope off Launiupoko, Maui. The National Oceanic and Atmospheric Administration's Hawaiian Islands Humpback Whale National Marine Sanctuary launched a rescue effort with the assistance of the Coast Guard and state Department of Land and Natural Resources.

NOAA officials found hundreds of feet of heavy gauge yellow line emerging from both sides of the whale's mouth. The line crossed tightly over the whale's head and formed a knot and two lengths, one with a bundle of gear at the end of it, trailed hundreds of feet behind the whale, NOAA said.

Officials delayed a rescue effort because of rough seas, but they were able to get close enough to the whale to tag it with a telemetry buoy. On Dec. 2, NOAA found that the young whale was accompanied by two adult humpbacks, which made a rescue effort potentially dangerous, NOAA said.

It didn't help that the young whale was highly mobile, despite being tangled in the rope, NOAA said.

On Sunday, rescue crews were able to get close enough to the whale to attach a sea anchor, which is similar to an underwater parachute. The humpback began to slow and linger near the surface. Using a long pole, the team hooked a knife to the rope near the whale's back and slipped the blade between the rope and a cleft left by a wound from the rope.

The knife was then fastened to another sea anchor and after 10 minutes it sliced through the line, freeing the whale, NOAA said.

Officials retrieved about 350 feet of line that had entangled the whale.

NOAA said the whale swam away and appeared to be in good shape.

Previous disentanglements did not include other whales in such close proximity, NOAA said.