While on a research trip in Eden NSW, the Sea World Foundation team spotted the humpback whale entangled with rope and towing a Waverider buoy in the Tasman Sea.

The team had initially embarked from Twofold Bay in Eden to retrieve a satellite tag, but while travelling spotted the 10metre humpback whale in distress around 16km off the coast of Disaster Bay, between Green Cape and Cape Howe.

The Sea World Foundation team said the large whale was heavily entangled with rope and chain around its pectoral fins and body, with the large buoy being towed behind.

"It had been through a lot...it had quite a bit of skin off, it had bumps, bruises, it was bleeding all over the pecs around the eye," Sea World skipper Andy Mulville said.

"It was totally engulfed with rope, and our worst nightmare, chain - it had shackles and chain across its eyes so it probably hadn't opened its eyes in some time."

Mulville said the small team were only planning to retrieve a satellite tag so did not have a wealth of rescue equipment on board, but were able to put GoPros underwater to "see what we were dealing with".

"Fortunately, the team had their cutting equipment on board, and despite being understaffed, the specialised team were able to successfully remove all of the equipment from the whale in an operation which lasted around 15 minutes," the foundation later said in a media statement.

Following the release, the team monitored the whale for a short period before leaving it to continue its southern migration accompanied by two other whales.

The foundation said it had been "incredibly fortunate" for the team to come across this whale as it was highly unlikely to be spotted again, with the remainder of its migration heading south-east off the Australian coast continuing towards Antarctica.

"It's a strange feeling for our sat tag to have ended up hour and half away from where we thought it was, right beside an entangled whale," Mulville said about the encounter.

"The whale had two companions with it - they were actually holding it up when we first arrived.

"To see all three take off and keep heading south where they're supposed to, there's not a better feeling.

"It was a huge relief, and a pretty special day for everyone out there."