A Japanese tourist has died while snorkelling between the flags in shallow water at a patrolled beach at Green Island, near Cairns.

The 47-year-old man’s body was found about 2.40pm (AEST) yesterday on the seabed by tour operators with his mask and snorkel intact after his wife, who was reportedly on the beach, alerted lifesavers she had lost sight of her husband.

The couple travelled to the island in north Queensland as part of a Great Adventures tour, which is operated by the Quicksilver Group.

Group general manager Matthew Hurley said his crew began searching for the body – which took about an hour to locate – immediately after a lifeguard raised the alarm he was missing.

The body was then carried to the beach before being taken to a boat and returned to meet the coroner and police in Cairns.

“He was swimming between the flags on the public beach on Green Island, which is a well populated patrolled area with a lifeguard on duty,” Hurley said.

“No one reported any signs of anyone struggling or in difficulty.”

Hurley commended the efforts of those involved in the search, which included a number of vessels and people, but some had been hit hard by the tragedy and were undergoing counselling.

“All the staff that were involved did a fantastic job under very trying and stressful conditions,” he said.

“Some of those involved were certainly very distressed by the situation.”

The police and rescue helicopter arrived at the scene after the body had been located and recovered by Great Adventures.

Mr Hurley said he expected an autopsy would be carried out in two or three days.

The dead man’s wife was being cared for by the tour agency, JTB Travel, which had organised the snorkelling trip.

Police say investigations into the incident are continuing.

The man is the fourth Japanese tourist to die in the waters off the island in the past three years.

Steve Davies, who is the director of operations of Big Cat Green Island Reef Cruises, said conditions on the water were good yesterday with winds of about 20 knots.

He said tourists wanting to take part in water activities signed indemnity forms and watched safety videos in English with Japanese subtitles before snorkelling.

Green Island is the most popular destination on the reef and features heavily in Queensland tourism promotions in Asia.