A social sea lion has struck up an unlikely friendship with a dog after the playful pair were captured frolicking in the ocean together just metres from shore.

Ryan Waldock had been walking his four-year-old dog Asta at Fremantle’s South Beach when he noticed the pup was overly excited about something in the water.

Despite being two completely different species, marine skipper Ryan said the unlikely pair looked the best of friends as they frolicked in the water.

Atsa, a ridgeback cross, began jumping into the waves when she spotted her aquatic friend

Asta was very curious about her new friend at Fremantle's South Beach in Western Australia

The unlikely pair looked the best of friends as they happily frolicked in the clear blue water

'She went for a swim and the sea lion literally just came straight up to her. It was a really good interaction,' he said.

'They were swimming together for about a minute. They were both really calm and happy.

'Asta was very curious and I think the seal felt the same. They were both checking each other out.'

Mr Waldock said at first when Atsra was getting excited about something in the water he had no idea what was going on

Mr Waldock has been taking his dog Astra (pictured) for walks along the beach countless times but he had never seen a sea lion this close before

Mr Waldock said it was the first time he had ever seen a sea lion that close before.

According to the Australian Marine Conservation Society, the rare species are native to Australian waters and are currently endangered – with only around 11,000 Australian sea lions left in the wild today.

'It is such a beautiful beach. It’s not every day you get to witness something like that.

'All my friends and family were quite jealous that I got to see it with my own eyes, but everyone really loved the video.

'I felt so lucky to see something so amazing. It was unforgettable.'