A former cruise worker has revealed the secret bars on a ship where staff indulge in wild parties — and guests have no idea.
American man Brian David Bruns, a former cruise ship crew member and best-selling author behind the Cruise Confidential book series, told the UK's Express about the wilder parts of the ship guests couldn't access.
There was usually one main crew bar on a ship, he said, and occasionally a separate lounge just for officers.
"Most ships nowadays have the crew bar on zero deck, which is at the waterline," he said.
"Crew bars vary widely, depending upon the layout of the ship and where they're located.
"In the case of one Royal Caribbean ship, the entire back deck near the waterline was open to the air.
"I believe the ship was of French design, which would make sense: just off the extensive dining area for the crew was an expansive, teak-planked open-air patio spanning the entire width of the ship.
"Most crew bars have minimal dance floor space, however. They aren't nightclubs, so much as a neighbourhood dive.
"They're loaded with chrome and shiny baubles, with thumping music."
Bruns said many members of crew stocked up on cheap, duty-free alcohol and enjoyed it on the ship, and some cruise companies hosted legendary parties for staff where people really let their hair down.
"Carnival was the best in this regard," he said. "Twice a month they had a big crew party, once in the crew bar and once they actually closed a guest lounge in favour of the crew.
"These parties were from midnight until 2am, and had free liquor. My understanding is that in the last few years they've stopped giving away the free hard liquor. This was wise on their part.
"These parties were the wildest things I've ever seen — and I live in Las Vegas. When given only two hours to cut loose, people really, really did so."
He warned parties weren't safe for passengers to sneak into, as they were often underneath the ship's bridge, which was strategically kept unlit for the ship's navigator, and therefore "unsafe for guests", he said.
Hidden staff parties are just one of the many secrets lurking on a cruise ship.
Guests may be surprised to know that 200 people died on cruise ships each year, and the secret code "Operation Bright Star" was used when it happened.
They also used the codes "Mr Skylight", "Alpha" or "Code Blue" when passengers died.
The body was then stored in a bag in the ship's specially designed morgue, which features large metal cupboards where the temperature is between two and four degrees.
About 20 people disappeared from cruise ships every year, usually presumed to have fallen overboard, and when that happened, "Mr Mob" or "Oscar, Oscar, Oscar" was announced to raise the alarm.
"Code Red" refers to an outbreak of illness, while "Code Yellow" and "Code Green" are less serious issues.