The lagoon is patrolled by lifeguards and is a popular destination for locals and visitors. (ABC: Daniel Battley )
A man and his five-year-old son, who were overseas tourists, have drowned at Airlie Beach, north of Mackay, in north Queensland.
Paramedics said the boy and his 30-year-old father were pulled unconscious from the water at the Airlie Beach lagoon about 4:00pm on Sunday afternoon.
They went into cardiac arrest and were rushed to Proserpine Hospital in a critical condition but died shortly after.
Police said they were overseas tourists who got into trouble in the water.
Police said they were still working to contact relatives of the man and the boy, who are believed to be from Asia.
Visitors to the popular Whitsundays tourist attraction said they were in shock, with one witness telling the ABC she saw people performing CPR on the pair for about 30 minutes.
She praised the efforts of lifeguards to revive the pair.
The witness said the images of the afternoon had been burned into her memory and she would never forget them.
The lagoon remains closed.
The Airlie Beach lagoon is patrolled by lifeguards and is a popular destination for locals and visitors.
A report will be prepared for the coroner.