An enormous rotting whale carcass has attracted an exceptional collection of normally antisocial saltwater crocodiles.

Kimberley chopper pilot John French has been flying over the region for 30 years and said he had never seen anything like it.

"We knew there were three, maybe four, resident crocs in the area but I was quite surprised to count 14 around the dead whale," he said.

Mr French was taking tourists from a charter boat on a sightseeing flight around Montgomery Reef, a 400-square kilometre area about 20 kilometres off the remote Kimberley coast, on Thursday..

The area experiences some of the largest tidal movements in the world and he was flying over reef and sandflats exposed by the low tide when they noticed the dead whale.

"We flew down to take a look and we counted 14 crocodiles, including two that came out of the whale's belly," Mr French said.

Humpback whales are very common in the area during the cooler months when they use the surrounding Camden Sound marine park for calving and mating.

Mr French said he had seen about 10 dead whales over his three decades in the area, which he believed had all died naturally.

"There was another dead whale that the tide lifted onto Montgomery Reef about two years ago," he said.

"Every time the tide came in, it rolled the body around to a different part of the reef until it rotted away."

Crocodiles crowd around a dead humpback whale left on a Kimberley mudflat by large tides. ( Supplied: John French )

Big crocs dwarfed by whale

In one photograph, what looks like a small lizard lying alongside the whale carcass is actually a 3.5-metre crocodile.

Mr French said this showed the whale was a full-grown adult.

"We hovered right next to the big croc, but you don't want to get too close because they will try and grab the helicopter skids," he said.

"That croc was 3.5 metres long, so if you can imagine a person alongside, [they] would be a lot shorter."

Even with the downdraft of the chopper, the smell of the rotting carcass was a bit much for some of Mr French's passengers.

"We flew down one end and it stunk; it was like whale soup around it, and the crocodiles were just in their element," he said.

The feeding frenzy will intensify with each high tide when sharks will join the crocodiles to feast and Mr French expects the whale carcass will soon disintegrate.

"When the tide comes in the sharks will hit it really hard," he said.

"So as soon as it rots enough, the tide will take it."