Snorkellers identified as being "at-risk" will have to wear flotation devices while diving at the Great Barrier Reef and other waterways as part of a raft of new safety measures.
The changes come after 10 people died in Queensland waters while diving and snorkelling between July and December last year - double the industry average.
Tourism operators will now be allowed to request declarations from people identified as at-risk before they enter the water.
Those people will also be required to wear flotation devices as well as a different coloured vest or snorkel so they can be easily spotted from a vessel, which must have an automatic external defibrillator on board
Association of Marine Park Tourism Operators chief executive Col McKenzie said the changes would result in a safer experience for tourists.
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"Our industry strives to ensure world's best practice and once again we have achieved this," Mr McKenzie said.
Industrial Relations Minister Grace Grace said a new recreational diving code of practice would also be announced in coming weeks.
An economic report in June 2017 valued the Great Barrier Reef at $56 billion, with the World Heritage-listed icon contributing $6.4 billion to the Australian economy each year.
