On 25 January, 1998, married couple Tom and Eileen Lonergan were part of a scuba diving group which were out to explore a part of the Great Barrier Reef when they realised their boat had turned back for shore without them.
Stranded about 40 miles from the Australian coastline, the couple were stuck hoping that someone from the vessel's crew or the group of 26 divers would notice they were missing. Tragically, nobody did.
The alarm was only raised two days later when their bags were found on board the boat and the crew finally realised they had missing people out in the sea, prompting a major search effort.
Advert
Search efforts found a dive slate with a plea for help written on it, saying:"[Mo]nday Jan 26; 1998 08am.
"To anyone [who] can help us: We have been abandoned on A[gin]court Reef by MV Outer Edge 25 Jan 98 3pm.
"Please help us [come] to rescue us before we die. Help!!!"
They'd written the message the day after they were left behind and the day before anyone realised they were missing.
Advert
No sign of the bodies of Tom or Eileen was found, though some of their equipment washed up on shore in the months that followed their disappearance.
Eileen's wetsuit was found about a month after the American couple had gone missing, with tears in it thought to have been caused by coral. Other items recovered include dive jackets, tanks and one of Eileen's fins.
Boat captain Geoffrey 'Jack' Nairn was charged with manslaughter but later acquitted, and he said that he'd delegated the headcount to a crew member who'd become confused after two people jumped into the water part-way through.
There have been a number of theories surrounding the fates of Tom and Eileen Lonergan, with some of them sounding plausible and others much less so.
Drowning or dehydration
The simple fact of the matter is that if you strand a person in the middle of the ocean they're either going to die of dehydration from having no clean water to drink or they're going to become too exhausted to remain afloat and will end up drowning.
Advert
This is perhaps the most likely outcome for the unfortunate couple, with Eileen's father John Hains saying this was one of the outcomes he expected from the tragedy.
Eaten by sharks
The other theory Eileen's father suggested was that the couple were eaten by sharks that dwell in the waters off the Australian coast.
A number of species of shark call the Great Barrier Reef home and it wouldn't be beyond ridiculous to think this is what happened to them.
Advert
This is the theory which served as the inspiration for the 2003 movie Open Water, which is based on the story of Tom and Eileen.
However, the equipment which washed up to shore didn't show signs of damage consistent with a shark attack, as the wetsuit discovered was thought to have sustained damage from tearing on coral instead of being bitten by a denizen of the deep.
Suicide pact
In the days before they went missing the couple's diaries contained some worrying entries, with Eileen writing that her husband wanted to have 'a quick and peaceful death'.
Advert
She later clarified that 'Tom's not suicidal' and instead said 'he’s got a death wish that could lead him to what he desires and I could get caught in that'.
This theory would seem to be on shaky ground considering the couple were left behind by accident and would have been found if not for the mistaken headcount that was beyond their control.
Let alone the fact they left a message appealing for help.
Their families also disputed suspicions of suicide, claiming the words had been taken out of context.
Faking death
This is the most ridiculous and unserious theory behind what happened to the couple.
Being left behind in the sea many miles from shore is dangerous enough, so making it be part of a plan for the couple to fake their deaths and disappear seems unlikely.
There were several reported sightings of the couple after they went missing but none of them could be verified, while they'd also left behind all of their belongings.
Suspicions of suicide or faking their deaths were dismissed by a coroner, and their bank accounts weren't accessed after they went missing.
Drowning or dehydration would seem to be the most likely outcomes.
Joe Harker