75-year-old Japanese woman was pulled from the water about 2:00pm yesterday at Moore Reef, off the coast of Cairns in far north Queensland.
Queensland police said the woman was on a day trip with Sunlover Reef Cruises.
Today the company issued a statement expressing "deep sympathies to the family and friends of the Japanese woman who tragically passed away".
"Our crew have being offered support and professional counselling," it read.
The woman is the 10th person to die on the reef in the region this year and the fifth since early November.
The Association of Marine Park Tourism Operators said the majority of the victims were elderly and had pre-existing medical conditions.
Spokesman Col McKenzie said snorkelling the reef is on many people's bucket lists.
"While we are very proud of the fact we have the safest snorkelling in the world, we've got to sit down and have a really close look at all these events and see if there's anything we can do," he said.
Mr McKenzie said Workplace Health and Safety released an updated risk-briefing document in all major languages, which highlights the risks associated with snorkelling and diving.
"But at this point in time, there has been no substantive changes made," he said.
"We're at a bit of a loss as to what we can do."
Mr McKenzie said 10 fatalities in one year is double the industry average.
"Maybe we need to tweak the regulations somewhere," he said.
"We've got to be very careful that we don't discriminate by age or take a reactive position when that's not justified.
"I think it's possible that we could bring in place a rule that says that everybody over a certain age has to acknowledge that they have been told of the risks associated with snorkelling and diving."
Mr McKenzie said compulsory medical checks for divers and snorkelers would be cost prohibitive, with dive medicals in Cairns costing about $80.
"Can you imagine a million passengers being told they've got to go and have a dive medical before they get on a boat? They simply won't do it," he said.
"If they want to go and see good coral, they can go and see it anywhere in Asia as well, so we've got to be cost-competitive.
"I don't believe there would be any change in the number of people dying, they would simply die somewhere else."
In November, a 60-year-old British tourist died while scuba diving at Agincourt Reef and two French tourists died after suffering heart attacks while snorkelling together at Michaelmas Cay off Cairns.
Both had pre-existing medical conditions.