A huge humpback whale briefly scooped a kayaker in its mouth in the seas off the coast of southern Chile before spitting him out unscathed in a dramatic incident caught on camera.

It happened in Bahía El Águila near the San Isidro Lighthouse in the Strait of Magellan.

Adrián Simancas was kayaking with his father, Dell Simancas, when the massive whale suddenly surfaced, trapping the young man and his yellow kayak in its mouth for a few seconds before letting him go.

"Stay calm, stay calm," Dell can be heard saying in the footage, which has become one of the most striking and terrifying images in Chile in recent years.

"I thought I was done for, that I was dead. It was like three strange seconds down there," Adrian said.

He described the "terror" of those few seconds and explained that his real fear set in only after resurfacing.

"I felt like I was being lifted, but it was clearly too strong to be a wave," said Simancas.

"When I turned, I felt something blue and white passing close to my face, like on one side and above.

"I didn't understand what was happening. Then everything … I went under and thought I had been swallowed."

Adrián Simancas and his father Dell Simancas speak about the encounter. – Reuters

Luckily, the whale quickly spat out Simancas unharmed. His father, in another kayak, caught the whole thing on camera.

"I turned on the camera and heard a wave crash behind me, loudly. When I turned, I didn't see anything," Dell said.

"So that was the only moment of real fear because I didn't see Adrian for about three seconds.

"Then he suddenly shot out without the kayak, and a second later, the kayak emerged, and then I saw the fin of something."

Despite the terrifying experience, Dell remained focused, filming and reassuring his son while grappling with his own worry.

"When I came up and started floating, I was scared that something might happen to my father too, that we wouldn’t reach the shore in time, or that I would get hypothermia," Adrián added.

After a few seconds in the water, Adrián managed to reach his father’s kayak and was quickly assisted. Despite the scare, both returned to shore uninjured.

"I thought it had swallowed me," Adrián told his father in the video, still in disbelief.

The incident happened in Bahía El Águila, in southern Punta Arenas, about 3000km (1600 miles) from Santiago.

The Strait of Magellan is one of the main tourist attractions of Chilean Patagonia, known for adventure activities.

Its frigid waters pose a challenge for sailors, swimmers, and explorers who attempt to cross it in different ways.

Although February is summer in the Southern Hemisphere, temperatures in the region remain low, with minimums dropping to 4C (39F) and highs rarely exceeding 20C (68F).

Direct attacks by whales on humans are extremely rare in Chilean waters.

However, in recent years, there has been an increase in whale fatalities due to frequent collisions with cargo ships, and whale strandings have become a recurring issue in the past decade.