The Coast Guard is searching for a juvenile humpback whale last seen Tuesday entangled in netting off Kauai.

A radio message was sent to mariners to keep an eye out for the whale, estimated to be 35 to 40 feet long. Helicopter tour companies also were notified.

About 10:30 a.m. Tuesday, the Coast Guard said a helicopter tour company spotted an entangled whale about 1,000 yards off Honopu Point on Kauai’s Na Pali Coast.

A small Coast Guard boat on a routine patrol on the west side of the island diverted to the scene and also spotted the whale. It appeared to be tangled in about 60 to 80 feet of line with a white buoy attached, said Eric Roberts, marine mammal response coordinator for the Coast Guard.

The Coast Guard crew did not have equipment on board to disentangle the whale, and crewmembers monitored the humpback for three hours.

Roberts said they received the equipment from the Hawaiian Islands Humpback Whale National Marine Sanctuary after the vessel returned to the station yesterday. The whale was last seen two nautical miles off Kukole Point, Kauai, about 2 p.m. Tuesday. The whale was heading southeast toward Waimea.

Sanctuary officials reported the mammal appeared slightly emaciated, but in fair condition. It’s still healthy and strong, Roberts said.

The Coast Guard is attempting to relocate the whale based on its last known course and speed. If spotted, a crew will be deployed to disentangle the whale.

The whale was initially seen traveling with a companion that was not entangled. Sanctuary spokeswoman Christine Brammer said the companion was not seen with the juvenile whale when a tour operator reported seeing it off Port Allen Harbor around sunset yesterday.

"It’s hard to say how far it could’ve traveled overnight. They move between islands," she said.

Anyone who has information on the location of the whale is asked to call the NOAA Marine Mammal Hotline at 888-256-9840.