In her deep research into sex crimes on cruise ships - and also the very particular and distinct culture on board these floating mega-liners - Dr Jill Poulston, a tourism academic, saw a few written lines from 1928 that piqued her interest.
She read Hotel Life and Personality by American sociologist Norman Hayner; he studied the way 1920s people behaved in hotels. It was a "moral holiday" guests booked in for, Hayner wrote. The "bonds of restraint" could be released - especially sexually. Poulston saw a strong connection to cruise ships in Hayner's ideas about hotels.
Cruising is in the middle of a worldwide boom. It grew 4.5 per cent last year, according to industry analysts Cruise Market Watch, to a global value of $US36 billion ($39 billion). In Australia, almost 700,000 passengers went on a cruise last year in an industry worth $830 million. In 2011, passenger numbers here grew by 34 per cent, making it the biggest market outside the US.
But as outlined in a recent Australian parliamentary report into crimes at sea - called Troubled Waters - it is also a paranoid and defensive industry, "acutely sensitive to customer perceptions and concerns, particularly relating to health and safety".
Bad cruise news is never far away, especially around safety, health and crime. The Brimble case in 2002 remains in the memory of most as a horrific crime. Brisbane mother Dianne Brimble died in 2002 on board a P&O cruise ship called Pacific Sky, which now sails renamed and out of sight through European ports. Brimble was administered fatal levels of the party drug Gamma Hydroxybutyrate and photographed. While an inquest identified eight people of interest, no manslaughter convictions were able to be secured; they were able to move possessions out of their cabins during the investigation while Brimble's family waited four years to get her fare refunded.
Serious issues around the ship's party culture were raised along with questions over the complexity of laws at sea, treatment of the victims' on-board family, availability of drugs and alcohol, on-board security and the preservation or otherwise of the crime scene.
Most recently was the mysterious couple-overboard case of paramedic Paul Rossington and Kristen Schroder from the Carnival Spirit near Sydney, in May. Last month an Italian court jailed four crew members and a company manager over the 2012 Costa Concordia sinking in which 32 people died.
In February this year a Carnival ship called Triumph lost power after an engine room fire - 4200 passengers drifted for days in the Gulf of Mexico with raw sewage seeping through the walls and carpets.
The chairman of the parliamentary standing committee, Labor's Graham Perrett of the Brisbane seat of Moreton, says the cruise industry, which is largely self-regulated, has made some improvements since Brimble's death.
But his committee's recommendations to the industry were extensive. It included giving passengers brochures with safety information, mandatory reporting of all crimes with data kept by the Australian Institute of Criminology and improved protocols around crime scene preservation. It also recommended the new government vote in favour of better evidence collection methods for crimes and missing people at an International Maritime Organisation assembly in November.
Submissions to the committee revealed police have scant data on crimes at sea. The Australian National Council on Drugs said it had no data on cruise ships.
Self-regulation of a multimillion-dollar growth industry, Perrett says, makes him very wary. "When people investigate themselves and when the results of those investigations can be made public and harm those doing the investigation there is the opportunity for cover-up," he says.
"The ball is in the court of the cruise industry now. They have to be guided by the actions of the worst, not just the good behaviour of the best. Are they crossing their fingers and hoping the Brimble-type scenarios are from the past? Or are they changing their processes and procedures to make sure it doesn't happen again?"
Poulston, the head of the hospitality department at the Auckland University of Technology and an associate director of the New Zealand Tourism Research Institute, goes back to that concise phrase of Norman Hayner's from 1928 - the "moral holiday", for both crew and passengers. "They enter a cocoon," she says. "People go into a different mode."
With Professor Ross Klein, an American sociologist and administrator of travel advisory website Cruisejunkie, she has written a report called Sex At Sea: Sexual Crimes Aboard Cruise Ships. It was submitted to the parliamentary standing committee. She says the cruise industry has sexualised romance and often bases marketing on the idea that a cruise has sexual possibilities.
The names of cruise ships - Adventure of the Seas, Allure of the Seas, Carnival Ecstasy, Carnival Fantasy, Diamond Princess, Island Escape - can be suggestive and contain subliminal sexual messages, she says.
The crew play their part. She says they ("young adventure seekers and migrant workers") can also feel immune from the laws of the real world. Uniforms, she says, create a power imbalance in an already sexually charged atmosphere.
According to data obtained through freedom of information from the FBI in the US by Klein and used in the Sex at Sea report, one cruise operator with 22 ships had 92 sex-related crimes in 2008, an average of four per ship. Poulston says crime on cruise ships in general is "significantly" more common than on land, a charge cruise operators deny.
The same FBI data revealed that most perpetrators were male crew members and most victims were female passengers and the most common location for alleged sexual crimes was the passenger's cabin.
"No police, no elected representatives," she says. "A cruise is a commercial town away from everything else with people determined to have a good time.
"Everything is unnatural."
The Australian industry is dominated by the world's largest cruise company, Carnival Corporation, nicknamed "Carnivore" by its detractors. Based in Miami, it owns the P&O, Cunard, Princess, Carnival, Holland and Costa lines. The Costa Concordia infamously crashed into a reef and partially sank off Italy last year.
In recently announcing the arrival of another 2600-capacity ship, the Carnival Legend, to sail from Sydney from next month, the company's director for Australia and New Zealand Jennifer Vandekreeke said: "There is a great fit between the Australian personality and Carnival Cruise Lines, both being playful, outgoing and fun loving."
The second major player in Australia is Royal Caribbean, the world's second-largest cruise company. It outlined big ambitions for Asia and Australia in its annual report last year.
The overwhelming majority (86 per cent) of passengers on cruise ships departing from Australia are Australians; popular two-week routes include the South Pacific, New Zealand and around the Australian coast. Cruising is cheap. A 10-night Carnival Pacific Islands cruise from Sydney next month visiting Fiji, Noumea, Lifou and a "mystery isle" is $1390 for a mid-priced "balcony" room.
Dianne Brimble's husband, Mark Brimble, has become a lobbyist for cruise ship victims since her death, heading up the Australian arm of the International Cruise Victims group. He says the industry has improved since the shadowy circumstances of his wife's death - and the investigations into it - but it still lacks transparency.
"I don't think they should self-regulate," he says. "It gives the corporation too much responsibility in a murky and somewhat confused environment. The Australian consumer is denied rights they are given when on the mainland. I don't see how you can say they have sufficient corporate responsibility to self-regulate."
The laws covering incidents at sea are notoriously complex. Australia can prosecute within a maritime zone off our shores in the Crimes at Sea Act. Which agency prosecutes under that act depends where the ship was at the time and whether it was coming towards or sailing away from Australia.
If the crime happens on a ship outside the 12-nautical-mile zone and it is moving towards a foreign port, says leading maritime law academic Associate Professor Kate Lewins, of Murdoch University, "things get very tricky". She calls it a "legally murky zone".
Other nations can also claim a right to investigate and prosecute. The ship's flag state - such as Panama, the Bahamas or Liberia - can retain jurisdiction to prosecute under international law. The United Nations Convention on the Law of the Sea (UNCLOS) permits others, such as the next port the ship visits, to have jurisdiction. UNCLOS, however, limits the jurisdiction of coastal states to crimes occurring on board ships within the 12-nautical-mile territorial sea - a much narrower area than that claimed under Australian law.
"Australia could improve its claim to criminal jurisdiction over crimes on board ships where there is an Australian victim and there is no other connection to Australia," Lewins says.
If a foreign-registered ship was going from Singapore to Hong Kong, she says, and an Australian was killed, the current Crimes at Sea Act would not give Australian authorities a right to prosecute. "In that case a person could challenge Australia's right to prosecute them." She says most passengers know nothing of the right laws while on board and underestimate the complexity into which they step.
Yet passengers queue up at the gangplank in increasing numbers. Last year was the eighth consecutive year of double-digit growth in the Australian industry.
Neither Carnival nor Royal Caribbean would comment directly for this story, referring all inquiries to a Sydney PR firm representing Cruise Lines International Association, an industry group with most operators as members.
The industry's consistent line is it is the safest form of "leisure transportation" and denies a culture of cover-ups or lacklustre investigations. It points to the significant improvements operators have made since the Brimble case on Australian lines; Carnival, in its submission to the parliamentary standing committee, called these a "complete transformation ... to rebuild trust".
The most significant of these, Carnival submitted, were: responsible service and consumption of alcohol, zero tolerance of excessive behaviour, better trained security, new crime reporting procedures with Australian and foreign police, security cameras, drug policies, banning schoolies' cruises and new company senior management. The crime rate on board ships was "significantly less" than on land, according to the submission.
CLIA said the cruise operators therefore had already done most of what the parliamentary standing committee recommended. It did not know why critics of the industry including cruise victims, academics and politicians still maintained cruising could be perilous.
This was "misinformation", according to Libby Moffet of MG Media Communications, speaking for CLIA. "It makes no sense for cruise lines to cover up crimes at sea. In fact cruise lines have every incentive to have alleged crimes thoroughly investigated by law enforcement authorities ... CLIA continues to focus on improvements in its already robust security practices."
The bipartisan standing committee's recommendations will go to the new government after the election and some or all of it may become law.
In the United States, new laws passed in 2010 - after congressional hearings and lobbying by victims' groups - came down hard on cruise operators, legislating they must not only collect crime data but also publish it. The results show higher than previously known levels of rape and sexual assault, according to cruise victims' lobby groups.
There is no mandate yet for Australian-based operators to publish such data. The US figures for Royal Caribbean, buried in a "Stewardship Report" on its corporate website rather than its travel portal, claim that in 2012 eight guests or crew alleged rape, nine alleged sexual assault and three alleged assault. The report stresses they were allegations and might not have been true. No details of subsequent investigations were given and no details of ships or routes or the nature of the allegations were given.
The cruise operator says in the same year five people went overboard from its ships but all, it maintains, were intentional. It said US data indicated suicide levels in the general community on land had gone up accordingly "in the last decade".