Thomas Joseph Lonergan (born 28 December 1964) and Eileen Cassidy Lonergan (formerly Hains; born 3 March 1969) were an American married couple. They were accidentally left behind in the Coral Sea, near the northeast coast of Australia, on 25 January 1998. This happened during a scuba diving trip with a group on the MV Outer Edge. The crew of the boat did not realize they were missing until two days later, on 27 January. Despite search efforts that uncovered personal belongings believed to belong to the Lonergans, they were never found. It is assumed that they died, although their exact location remains unknown.

The disappearance and tragic fate of the Lonergans had a significant impact on the dive industry in north Queensland. It led to a loss of confidence in the industry and prompted stricter safety regulations for diving boats in Australia. Additionally, their story served as the inspiration for the movie Open Water, released in 2003.

Thomas Joseph Lonergan and Eileen Hains, who both attended Louisiana State University, got married in Jefferson, Texas on June 24, 1988.

The Disappearance

On January 25, 1998, Tom and Eileen Lonergan departed from their hostel in Cairns, Australia and traveled to Port Douglas, located in the northern region of Queensland. The couple, avid scuba diving enthusiasts, had recently completed a three-year stint with the Peace Corps and planned to enjoy a vacation in Queensland before returning to their home in Baton Rouge, Louisiana.

Joining a group of 24 other individuals, Tom and Eileen boarded the Outer Edge, a vessel owned by Geoffrey Nairn, and set sail towards St. Crispin’s Reef in the northeast. During their time aboard the Outer Edge, the Lonergans informed Katherine Traverso that they intended to venture off on their own and pursue their own scuba diving activities.

The Lonergans were participating in a scuba diving excursion at St. Crispin’s Reef in the Great Barrier Reef, Australia. They were part of a group that went diving at the reef.
Around 2:30 pm, the boat made a stop at the tip of the reef. It was a beautiful day, and everyone enjoyed diving and having a good time. After approximately 40 to 60 minutes, everyone returned to the boat, and the boat’s owner, Nairn, counted a total of 26 people. However, Tom and Eileen were not among them.

Unfortunately, when the boat carrying the group departed the dive site, the Lonergans had not yet returned from the water. Neither the crew nor the passengers onboard noticed their absence.

Upon reaching Port Douglas, all 24 divers disembarked from the boat. However, the Lonergans’ two bags were left behind. One bag contained dry clothes and glasses, and the other bag was empty, previously used for diving gear. The crew members of the Outer Edge failed to notice that two diving tanks and weight belts were also missing.

During that time, the Lonergans had recently finished a two-year assignment with the Peace Corps in Funafuti atoll, a small island in the South Pacific nation of Tuvalu. They were now engaged in similar work in Fiji.

Investigations 

The Lonergans’ disappearance went unnoticed until January 27, 1998, when a bag containing their belongings was discovered on the dive boat. A large-scale search operation, involving both air and sea efforts, was initiated and lasted for three days.

In February 1998, a women’s wetsuit that matched Eileen’s size was found washed ashore in north Queensland. Analysis of barnacle growth on the wetsuit indicated that it had likely been submerged in the ocean since January. The wetsuit also had tears in the buttock and armpit areas, believed to have been caused by contact with coral.

Various theories emerged regarding their disappearance. Initially, there were suggestions that the Lonergans might have intentionally staged their disappearance. However, no activity was detected in their bank accounts, and they did not make any claims on their insurance policies.

Excerpts from Tom’s personal diary were discovered, which portrayed a man seeking a “quick and peaceful” d*ath. Eileen’s writings expressed her commitment to stay with Tom, regardless of the outcome. However, Eileen’s family members argued that the diary entries were taken out of context.

They claimed that only the pages supporting the su*cide theory were leaked to the press, while the majority of the diaries remained unread, except by the coroner, Port Douglas police, and the Hains family.

In June 1998, approximately six months after the Lonergans’ disappearance, additional pieces of their diving equipment were discovered washed up on a Port Douglas beach, about 75 miles (121 km) away from where they went missing. Among the recovered items were inflatable dive jackets with the Lonergans’ names, their compressed air tanks, and one of Eileen’s fins. A weathered diver’s slate was also found, which contained a distressing message stating their abandonment on A[gin]court Reef by MV Outer Edge on January 25, 1998, and their urgent plea for rescue before their presumed demise.

Dive slate which was found at Archer Point with message from missing divers Tom and Eileen Lonergan.

Eileen’s father, John Hains, later expressed his belief that the couple likely became dehydrated and disoriented, ultimately succumbing to drowning or sharks. During the inquest into their d*aths, experts speculated that based on the condition of the recovered gear, an animal attack was unlikely. Instead, it was suggested that the Lonergans might have suffered from delirium caused by dehydration, leading them to voluntarily remove their diving gear. Without the buoyancy provided by the equipment, experts testified that the couple would have been unable to stay afloat for an extended period, resulting in drowning.

The coroner dismissed the possibilities of su*cide or a staged disappearance by the Lonergans and formally charged Geoffrey Ian “Jack” Nairn, the skipper of the dive boat, with their unlawful k*lling. However, Nairn was later found not guilty. Nonetheless, his company, Outer Edge Dive, faced fines and ultimately went out of business. The government of Queensland responded to the incident by implementing stricter regulations, including the requirement for captains and dive masters to independently confirm head counts.

The 2003 movie Open Water was inspired by the Lonergans’ disappearance. The film is set in the Caribbean and shows two divers getting left at sea due to an incorrect headcount.

Sightings

In the months following their disappearance, numerous individuals claimed to have seen the Lonergans. A bookstore employee in Port Douglas reported that the couple visited the store and purchased maps and postcards two days after their supposed disappearance. Additionally, sightings of the couple were reported in a hotel in Darwin, which is nearly 3,000 km away from Port Douglas.

One particularly intriguing incident was a phone call made to the Outer Edge the night before the Lonergans vanished. The operations manager received the call, and it was Tom Lonergan on the line. Tom inquired about the boat’s itinerary, specifically if it would be visiting Agincourt Reef. As the manager confirmed this, Tom seemed increasingly concerned and repeatedly asked the same question. Around the same time, Lonergan contacted a worker at the Cairns Visitors Information Centre with a similar inquiry, specifically about the Quicksilver V, a charter boat, and whether it also traveled to Agincourt Reef.

Theories

1. The possibility exists that they managed to make it safely to shore in the isolated Far North but have not been located.
2. Another theory suggests that they intentionally staged their disappearance and were subsequently picked up by a boat in the area.
3. Some speculate that they may have been troubled and decided to end their lives in a suicide pact.
4. There is also the notion that they could have been attacked and consumed by sharks either as they were swept out to sea or while attempting to swim to safety.
5. Lastly, one theory proposes that Thomas and Eileen Lonergan tragically drowned after the dive boat departed without them, leaving them stranded at sea.