A pair of scuba divers has captured rare video and photos of a 2.5-meter (eight-foot) giant squid swimming in the waters off Japan's west coast.

Earlier this month, Yosuke Tanaka and his wife Miki, who operate a diving business in Toyooka city in the Hyogo region, were alerted to the squid by a fishing equipment vendor who had spotted it in a bay.

The couple took their boat out to reach the creature as it floated near a rocky shoreline.

"There it was. It was an enormous squid," Yosuke Tanaka told AFP on Thursday.

"We didn't see the kinds of agile movements that many fish and marine creatures normally show," he said. "Its tentacles and fins were moving very slowly."

The sheer size of the animal and its enormous eyes were striking, and Tanaka said he was imagining the power squid use to tackle whales, which are among their main predators.

"I could see its tentacles moving. I thought it would be dangerous to be grabbed hard by them and taken off somewhere," he said.

Giant squid are known to live in the waters around Japan, and occasionally wash ashore. But seeing them alive in the wild remains relatively rare.

The squid appeared weak and moved only "very sluggishly," Tanaka said. Pieces of its skin were peeling off from its trunk.

He said the experience would stick with him.

"It was very exciting. I think there is nothing rarer than this," he said.

"I have heard not a lot is known about this creature. I'd be happy if this helps us learn more."

© Agence France-Presse