Markham was on a small research crew from the Sea World Foundation that had a chance encounter with an entangled humpback whale off the coast of Disaster Bay in Eden, NSW.

The whale was "fully engulfed" in rope and chains after getting tangled up with a Waverider buoy. The team only encountered the whale when heading out to locate a satellite tag it had released off Eden the previous day.

"You wouldn't believe what happened, we were searching for this tag in the Southern Ocean and it led us to an animal in distress," Markham said.

"The animal was pretty calm for the most part, so we could get some really good vision underwater with the GoPro which helped us assess the situation and make a plan.

"We didn't have the backup we usually do, but everyone played a part who was on the boat. It's good that way where you learn to think on your feet and multitask."

Markham said Sea World Skipper Andy Mulville kept their boat in an ideal position to assess the entangled whale and make the necessary cuts needed to free it.

Although two humpback companions didn't make it too easy for them, the crew was able to clear away all the ropes and send the whale on its way.

"That feeling never gets old," Markham said.

"It's good to be able to contribute to the animals down here. It was cool to see them take off pretty much straight off towards Antarctica, it's pretty epic."

Mulville said the rescue was "an amazing effort".

"We had a limited crew and limited gear to stumble across this, so we were a bit nervous at the start," he said.

"But we were quite lucky to have Benny up the front and he was doing the job of about three people.

"He got the vital cuts done and also pulled that rope clear at the end, it was pretty special."

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