The idea of going over the side of a cruise ship is horrifying. One minute a person is safely on deck, and the next the passenger has plunged several stories into inky water, often never to be seen again.
It's a story that's been written more frequently now that cruising has become increasingly affordable with ships built to hold a small city's worth of people. But amid a growing chorus of accusations about security leveled at the cruise industry, insiders say passengers and crew need to take more responsibility for their own safety.
"There's been a lot more binge drinking than I've seen in the past," said Douglas Ward, a cruise expert who has reviewed the industry for 43 years.
Ward, who lives in Southampton, England, and has written more than two dozen editions of the "Berlitz Complete Guide to Cruising & Cruise Ships," told ABCNews.com that most people who go overboard do so at night after a bout of heavy drinking.
In the past few weeks, two people have gone overboard on major cruise ships. Jennifer Ellis Seitz, 36, went over the balcony of the Norwegian Pearl cruise ship Christmas night. While her family has said the Florida woman may have jumped, authorities are still investigating.
One week later, on New Year's Day, a man identified as Carnival Sensation employee Antonio Matabang of California went overboard -- fellow crew members who saw him fall off the ship near the coast of Florida reported it. The search for his body has since been suspended.
Because cruise lines do not report crimes and accidents to one central authority, it's difficult to gauge exactly how many people go overboard each year. One informal cruising Web site puts 2008's total at eight, down from 20 in 2007 and 22 in 2006.
"The overboards always seem to me to be from the larger ships," Ward said.
Those would be the "resort ships" that dominate the industry -- those run by mainstream lines such as Holland America, Carnival, Celebrity, Royal Caribbean International and Norwegian Cruise Lines that can carry thousands of passengers and crew at a time.
While cruises used to be only for the elite, larger ships and cheaper tickets have made them the vacation everyone can afford -- older people living on a fixed incomes, families with young children, college students.
"As the age range goes down, it's more a question of drink and showing off," Ward said.
In 2008, about 16.8 million people took cruises, more than 11 million of them Americans, Ward said. That's up from about 9.4 million cruise passengers in 1999 and 500,000 in 1970.
While each overboard incident typically makes numerous headlines, the number of people who actually go over the side of ship is tiny compared with the number of passengers carried safely.
"It's a very, very small percentage," Ward said. "Of course, we don't want any."
While Carnival hasn't released information on Matabang's disappearance other than to say it was searching the waters for an employee, Ward said he was told that Matabang had been standing on the ship's railing for a photograph, "which is absolutely forbidden" and "stupid on a moving ship."
While cruise ship personnel can't watch every guest at every moment, the cruise lines said they have been making security changes to accommodate the growing number of passengers.
Gary Bald is the senior vice president and chief global security officer for Royal Caribbean Cruises Ltd., the parent company of Royal Caribbean International and Celebrity Cruises among other brands.
Bald, the former head of the FBI's national security branch, said Royal Caribbean has always had security cameras on its ships, though the company has greatly expanded the number of cameras in the last several years, in some cases by hundreds per ship.
Royal Caribbean's Freedom of the Seas, currently the largest cruise ship on the oceans with room for more than 3,600 passengers, has between 700 and 800 cameras, Bald said. And most are motion activated.
While not all cameras are monitored all the time, the cameras switch on when movement is detected and record the 30 seconds before the movement begins and the 30 seconds after the movement stops.
The length of time those files -- now digital instead of the old analog tapes -- are kept varies, Bald said. Tapes of a passenger going overboard are kept indefinitely, while images from an uneventful cruise may be eventually purged.
Like many other of the larger resort-type ships, Royal Caribbean's ships also carry smaller rescue vessels that can be sent out to search if someone is known to go overboard.
Carnival responded by e-mail to questions about its ships' security, saying personnel receive specialized training in preserving evidence that the FBI supervises.
"Additionally, all security personnel receive ongoing training at regular intervals," the e-mail said. "Recurring training includes updates on any new security procedures, as well as training in specialized areas such as terrorism, bomb detection, crisis and crowd management, first aid, firefighting and fire prevention."
Norwegian Cruise Lines declined to answer specific questions but released a statement, saying in part, "We have a number of safety and security measures in place, including a safety and environmental management system that is used by our ships that details specific procedures to take when an incident occurs."
But even with improved security and training, accidents happen.
Ken Carver founded International Cruise Victims, an advocacy and support group for cruise crime and accident victims and their families, after his daughter Merrian Carver disappeared during an August 2004 cruise to Alaska aboard the Celebrity Mercury.
Carver, who at 72 has made ICV his new full-time job, said he got a phone call from Merrian's daughter saying her mother hadn't been returning phone calls. Unbeknown to the family -- Carver said his daughter was somewhat of a free spirit -- Merrian, 40, had booked the cruise and boarded on Aug. 27, as noted by credit card receipts and documents from Celebrity.
But cruise officials couldn't tell Carver whether his daughter had ever disembarked. And, he later learned, a cabin attendant reported to a ship supervisor that Merrian ceased using her room after the cruise's second night.
The supervisor never reported the attendant's findings.
"He was told to forget it and do his job," Carver said.
Merrian Carver was never heard from again. Carver said he's heard rumors over the years that his daughter was romantically involved with the supervisor who declined to report the cabin attendant's concerns, but said that would be "impossible to prove."
Carver said he hired a private detective and spent tens of thousands of dollars researching his daughter's last known activities before he sued Royal Caribbean Cruises Ltd.
In a statement, Royal Caribbean noted that an FBI investigation had concluded that there was no evidence of foul play regarding Merrian Carver's disappearance.
"During that same time, we learned from her father that Ms. Carver had emotional problems and had attempted suicide before, which she appears to have done on our ship," the statement read.
The cruise company ended up settling with Carver out of court for an undisclosed amount.
"Do I know what happened to Merrian?" he said. "God only knows."
Bald said the Carver incident spurred Royal Caribbean to make procedural changes, including requiring all passengers to swipe ship-issued identification cards not only when they get on the ship but when they get off.
That might have helped in the Carver case, because authorities don't know if she went overboard or if she left the ship on her own at a port of call.
"We learn from every incident," he said.
Still, Bald said, "we made mistakes in this and there's no denying it."
First, he said, there was a mix-up in communication about the surveillance tapes from Merrian Carver's cruise. Ken Carver was erroneously told the tapes had been thrown out just weeks after the cruise ended, which they hadn't.
The tapes, analog at the time, did not show any images of Merrian Carver at all, Bald said, but the tapes were put back on a shelf and eventually lost when they should have been saved.
The supervisor who'd apparently failed to report the cabin attendant's report of Carver's disappearance was terminated, Bald said.
Since Merrian Carver's disappearance, Ken Carver has been a vocal advocate for legislation on cruise industry reform.
Bills have been introduced in the United States in the last couple of years aimed at the cruise industry, including joint House and Senate bills that called for more uniform crime reporting and improved response.
So far, none of the bills have been passed.
Former U.S. Rep. Christopher Shays, a Connecticut Republican who was unseated in November's election, made cruise industry reform a personal project after following the case of George Smith, a Greenwich newlywed, who went overboard on a Royal Caribbean ship during his honeymoon in 2005.
Smith's case received national attention and prompted a congressional hearing and backlash against Royal Caribbean, which was accused at the time of taking a blase approach to the incident.
Shays told ABCNews.com that a cruise ship is "the place to commit the perfect crime."
"You don't need a major weapon, and your evidence disappears," he said. "They say they're a miniature city, but they don't have anyone on board who is capable of investigating a crime."
Shays described the cruise industry as "powerful" and said it has so far succeeded in blocking any attempt at reform.
But Bald scoffed at the notion that his cruise line, at least, doesn't do enough when crimes occur onboard.
"My answer to them is name one we haven't reported," he said. "And nobody can name a single one."
Most cruise lines, Bald said, signed a voluntary international agreement in 1999 that requires that all crimes to be reported to the law enforcement agency that has jurisdiction, depending on where the ship is at the time.
Maritime law also requires that all crimes aboard cruise ships to be reported to the country where the ship is flagged -- Greece, Panama and the Bahamas being the three most common flag states. In the United States, cruise lines have an agreement with the FBI and the Coast Guard to report crimes in U.S. waters or involving U.S. citizens.
Other countries, Bald said, have their own laws regarding crimes aboard cruise ships.
Former cruise ship employee Brian David Bruns, who wrote "Cruise Confidential" based on his experience as a member of the Carnival staff, said there are far fewer accidents on cruise ships than people would believe.
"But boy, it makes a great story," he said.
Bruns said he was working the midnight buffet in 2003 when a passenger went overboard near the Gulf Coast. Rumors, he said, immediately began swirling around the ship as it began circling back toward where the woman was last seen.
Rescue boats were let out, but the woman's body wasn't recovered until it washed up on shore sometime later. Bruns said he believed the woman committed suicide.
Bruns said it's easy to sympathize with the family of the person who went overboard and blame the cruise line, but in reality, "there's only so much defense you can set up to prevent people from going over rails."
Ward agreed. He sees room for improvement from both passengers and the cruise industry, though maybe more for the passengers.
"There's always room for improvement," he said. "And I think the industry could do a little bit more, particularly when it's related to safety."
Cruise ships should continue to install more cameras, he said. As far as increasing response time, Ward said ship searches are now immediate. If someone is known to go overboard, rescue procedures are started immediately, though it can take several nautical miles to get a ship completely stopped, and 360-degree turns need to be made gradually so as to not cause the ship to list in the water.
Bartenders, he said, could also be more aware of their customers' intake.
On the flip side, Ward said, passengers "just need to drink sensibly."
"They need to realize that ships are moving objects," he said, "and railings are there for a purpose."
ABC News is a division of the Walt Disney Co., which owns and operates the Florida-based Disney Cruise Line.