Sisira Gajanayake, 59, was found unresponsive with his 21-year-old son, Themiya Gajanayake, 25 minutes from the city last night.
The pair were on holiday with some of his colleagues, transport company Ventura Bus said.
Emergency services were called when the two men started “struggling to get out of the water” about 5pm.
Gajanayake’s friend Nakula Premaratine told 9News his death was a tragedy.
“We all went for a swim and then suddenly the water level (went) up and his son jumped in to save him,” he said.
“But unfortunately, they both couldn’t be saved.”
Premaratine said his 59-year-old friend was a “very kind-hearted person”.
“He was (always) helping everyone,” he said.
“It’s a very big shock for the Sri Lankan community.”
Gajanayak worked for Ventura in Melbourne for more than eight years.
Ventura said the “much loved” man had worked with the company for over eight years.
“Our thoughts are with Sisira’s family and his work colleagues from Melbourne that were holidaying with Sisira in Cairns at the time of this tragic incident,” Managing Director Andrew Cornwall said.
A Queensland Ambulance spokesman said the men were declared dead at the natural pools.
Police said there were no suspicious circumstances, and a report will be prepared for the coroner.