The Vision of the Seas set off for a week-long jaunt around the Mediterranean – but the trip soon turned into a floating hell for some passengers and crew. The cruise liner – which carried up to 2,500 passengers – set off from Barcelona and swung by Ibiza and Mallorca before returning to the Spanish mainland five days later.

Guests said they spotted people snorting cocaine “all over each other” on deck beds while others threw up in the pool and overboard. “It was absolutely horrendous,” one woman said.

“I’ve literally never seen chaos like it. People vomiting into the swimming pool, you would have to step across crashed out party goers on the way to breakfast and people snorting cocaine from the backs of their hands up on deck.”

Another passenger said that drug dealers were offering a £260 (US$345) ‘meal deal’ – which consisted of bags and bags of cocaine. “It was easier to get a bag of coke on board than it was to get a drink,” they told the Mail Online.

One holidaymaker said the out-of-control, hedonistic ship was “carnage on a new level of wrongness” before adding: “I’m surprised no-one died.”

While another man said being aboard the vessel was so horrifying that he got off when the boat docked in Ibiza and refused to get back on. “I will never ever again go on such a trashy trip. The crowd was very Geordie Shore. Utter rip off. I know of drug dealers making an absolute killing and running out as the demand was so high. We left after three days as it was a joke.”

Cruise staff reported being abused, and said that “guests walked around the ship half naked” and were “drunk and clearly on drugs.”

Anchored Cruises chartered the ship from operator Royal Caribbean Cruises (RCC). RCC said they do not tolerate drugs, sex, and other miscellaneous debauchery.

“We have a zero tolerance policy for the use or possession of illegal drugs on our ships,” a spokesman said. Ship charters are held to the same strict standards. We operate with the health and safety of our guests and crew as our highest priority, and we cooperate fully with law enforcement when we are aware of violations.”

Channel 4’s reality show centers around 10 young Britons in their 20s joining 2,500 holidaymakers on a luxury cruise liner-cum-party boat. There is no suggestion that anyone involved in the production of Shipmates was involved in any of the mayhem.

The broadcaster said it could not comment on the behavior of other passengers, but did say that the raunchy, wild incidents did not involve contestants for the show.

The five-part series, filmed over the five days from hell, will be shown on Channel 4 later in 2018.