When you take a dip in the ocean off Australia’s Gold Coast Seaway, the largest animal you could reasonably expect to encounter is usually a turtle. When you go whale-watching, the best you usually hope for is a glimpse of the majestic creatures from afar. But for one Australian couple swimming in the sea off South Stradbroke Island, both expectations were blown out of the water – quite literally! – by an incredible encounter with a mother humpback whale and her calf.

Brad Nicholls and Emmy-Rose Curtis – who both work for whale-watching companies – intended only to have a fun day swimming when they dove into the waves south of Brisbane, and to try out some new video equipment. What ended up happening, however, exceeded both their expectations and all their prior experiences with marine life. As ABC 7 News reports:

“We were just playing around underwater with the GoPros and all of a sudden there was something much larger than a turtle there,” Curtis told ABC. “We had no fins, no goggles; it was certainly not anything anticipated.”

For more than an hour, the mother and calf would approach the swimmers before diving deep into the water only to surface once again.

“Their movements were so gentle and so slow, almost like they were like ‘Oh, I don’t want to hurt my new friends,'” Curtis said. “In 10 years, I have never seen this type of behavior for whales with a boat, let alone with us in the water.”

While Curtis warns that people should not try to recreate the experience for themselves – Brisbane 7 News reports that “An adult Humpback weighs around 40 tonnes and they are 12 metres long. People have been killed swimming with them before.” – she also wanted to share the miraculous meeting with the world, showing how similarly the water-bound mammals can behave to humans. The whales even respond to Curtis’ attempts at communication, slapping the water with their fins when she does the same with her arm!

Until we can all safely and affordably swim the whales – according to Brisbane 7 News, “Commercial tour operators are applying for permits to allow passengers to swim with the whales.” – let’s learn about these creatures and live vicariously with Curtis and Nicholls in this video from Hefty.

If you can’t get enough of the footage from this incredible encounter – and who could?! – you can also watch this longer video directly from Ms. Curtis.