Two British tourists have drowned off the coast of a popular tourist town at the southern tip of the Great Barrier Reef.

A boy, 17, and a man, 46, were swept out to sea on Sunday while swimming at a beach without lifeguards in Seventeen Seventy – a town in Queensland named for the year Captain James Cook arrived in Australia.

The pair were declared dead at the scene after being pulled from the water by a police rescue helicopter.

An Australian man is also in a life-threatening condition after being swept out to sea, and was airlifted to hospital with serious head injuries.

While police revealed that the deceased were from the UK, their names have not yet been released.

“Sunday’s mission was a difficult one,” CapRescue, the emergency rescue service that found the three men, shared on social media – adding that the deaths had occurred “despite the best efforts of all involved”.

Police say the injured Australian man was from Monto, a town about 150 kilometres inland from Seventeen Seventy.

“We’re not sure whether the third person jumped into the water trying to perform a rescue,” Surf Life Saving Queensland’s Darren Everard told the Australian Broadcasting Corporation (ABC).

There is only one beach patrolled by lifeguards within a 50-kilometre radius of Seventeen Seventy.

Police are treating the drownings as non-suspicious and will prepare a report for the coroner.

One-hundred-and-seven people drowned in Australia last year, with 25% of them born overseas, according to Royal Life Saving Australia.

Australia’s coastal fatalities mostly occur around creeks and headlands at high tide when “it’s chaos in the water”, Everard explained.

Speaking to ABC, he encouraged tourists to “seek local knowledge” and swim between the flags.