Not his actual hat. One made by his Newcastle-based surf brand Foam Riders.

"Chris Hemsworth and Matt Damon are best buddies. They both live in Byron Bay, next door to each other," Mr Totterman said.

"They went on a surfing trip in WA [Western Australia] to a place called Red Bluff, which is right up in the desert in Carnarvon.

"Being such a small place, you pretty much camp on the beach. Everyone was like, 'Matt Damon and Chris Hemsworth are in town'."

Foam Riders supplies its surfwear to the local surf shop - Norwest Surf.

The surf store gave some Foam Riders gear to Carnarvon Visitor Centre to give to the movie stars as a memento for their trip.

"They've got our T-shirts and hats," Mr Totterman said.

When he received word that the stars had his gear, he thought: "That's great, but they'll probably never see the light of day".

"The next thing you know Chris Hemsworth is at the AFL filming Matt Damon [on Instagram] and he's wearing one of the hats.

"We were cracking up laughing. We thought it was awesome. It's not every day you get an actor wearing your gear."

The hat is branded with Carnarvon and its postcode 6701. This reflects the concept of localism in surfing culture.

"We do that on T-shirts as well. Locals love it because they can get shirts with their own postcode and images of their surfing breaks," he said.

Foam Riders surfwear is now sold in about 90 surf shops across Australia.