Nicholas and Adrian smile for a heartwarming father-son photo aboard a Great Barrier Reef cruise ship. Hours later one of of them would be dead after being swept away while snorkelling

A heartbreaking photo taken moments before an elderly man died on a family trip to the Great Barrier Reef has emerged, showing him smiling with his son.

Adrian Meyer, from Angaston in South Australia, died after he and a group of snorkellers were swept away by a strong current over the reef last Monday.

The 71-year old was with his son, Nicholas Meyer, and daughter Angela Henson about 60km off the coast northeast of Cairns when disaster struck.

Mr Meyer had travelled to Cairns to see the World Heritage Area as part of a belated 70th birthday present.

Dangerous weather conditions had swept the snorkelers far from the boat and a strong current prevented them from swimming back.

During the struggle with the current, it's believed Mr Meyer suffered a medical episode and was boarded onto a rescue vessel which sank a short time later.

A touching photo taken on board the boat just before the tragic incident unfolded shows Mr Meyer smiling while giving a thumbs up alongside his son.  

Nicholas said he initially had plans to return to Cairns to collect his father's remains but had since had a change of heart. 

'My poor mum doesn't fly and we're trying to support her right now,' he told News Corp. 

'She needs us. With all the traumatic events that have happened we've decided it'd be better to stay.'

It is understood Mr Meyer will be cremated a later stage but the family have not yet decided where they would like to place his ashes.

'It's still raw,' Nicholas said.

'Dad was an avid traveller and so am I. We think we'd like to continue his memory by taking a little piece of him everywhere we go though, so we'll see.'

Ms Henson described her father as a 'loving grandfather' with a keen interest in the outdoors.

'He always said, 'I love you.' His connection to nature really struck me', she said.

'He always loved to rattle off names of coral and fish.'

Ms Henson was adopted at five weeks old and only met her biological father five years ago. 

Nicholas said his father was a 'staunch environmentalist' and had been fascinated by the Great Barrier Reef.  

'We'd love to do something for conservation. That's something that's important for dad's legacy,' he said.

'But we're not sure. We're still trying to grieve and get over the shock of everything.'

Mr Meyer's memorial will be held Thursday, December 7, in the Barossa Valley. 

His death is being investigated by the Northern Coroner and Workplace Health and Safety.