Two mates enjoying a jet ski ride off the Gold Coast became unlikely wildlife heroes when they spotted a distressed humpback whale tangled in rope.

Ryan Cavanah and Luke Esson did not hesitate when they jumped in to help the huge marine mammal that was struggling in the water.

In footage posted to social media, the pair said they noticed the whale was still in the water, so they went to check on it.

“That’s when we saw its tail was tangled in rope,” the video stated.

“The rope was cutting into its tail.”

The pair worked to loosen the rope from the whale’s tail but it wasn’t moving. so they carefully cut it free.

“(The whale) started swimming slowly away after it was freed,” they said.

“We have no idea how long it had been tangled.”

“We love our whale watching and our turtle exploring, we go scuba diving all the time,” Mr Esson told the Today show.

“We saw this whale in distress on the surface of the water, and first when I jumped in, I realised it had a bit of rope and fishing line around its tail.”

Mr Esson said the whale looked malnourished, was placid and moving slowly when they approached it.

“We did our best to help it, get it the healthiest it could be,” he said.

“Ryan’s really good underwater, he’s got a got a really good breath hold, so he jumped in and cut the line.”

Mr Cavanah said they had been out on a jet ski all morning watching whales jump and put on an amazing show.

“We were cruising back in and saw it struggling, and we jumped in just to get some footage of it and see how bad it was, and then we noticed it was just a rope around the tail, and it was an easy fix with a knife,” he said.

“We thought, while we’re there, it was safe, it was tired, and it was something we could do safely without putting ourselves in danger.

“We could give back a little bit to the whales that always give us such a good experience every weekend on the water.”

He said the humpback was moving along quicker than the footage showed and it was tricky to keep up with it.

“It was obviously exhausted, it hadn’t eaten in ages, so God knows how long it was swimming along with that all that rope around its tail,” Mr Cavanah said.

“It had almost cut the tail off, it was basically destroying it.”