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The cruise industry prides itself on its service, and crews are praised the world over for knowing exactly what their guests want.

But behind the smiles, some are seething over the way passengers behave.

A new survey reveals what really gets cruise ship staff up in arms.  Business Insider spoke to 39 current and former cruise ship employees to find out what they think are most annoying things passengers do on a cruise.

Most said that the majority of passengers are pleasant  – but it’s just hard to be on your best behaviour all the time, isn’t it?

So what are their biggest gripes?

Returning to cruise ship late

We saw how it can be devastating and heartbreaking and it is now revealed to be also annoying.

“What’s the most annoying thing passengers do? Not paying attention to the time they had to be back to the ship when in port,” said Chad Stone, a former production manager for Seabourn Cruise Line.

“This was a massive deal because we would end up paying more in port fees if we stayed too long, or we would end up having to wait for larger ships to leave, putting us in a large queue of departing ships. The captain would have to make up for it enroute, making for a bit rougher of a ride to the next port.”

No one wants the hassle that comes with missing their ship while on holiday. Be sure to include extra time in your schedule in case of unforeseen delays and return to your ship early when possible.

Bad hygiene

“When they don’t wash their hands after going to the toilet, or grabbing food directly from the buffet with their hands,” a Royal Caribbean Cruises employee said.

Not the buffet! Thousands of passengers visit the buffet daily and could easily become ground zero of a viral outbreak. Maintaining impeccable hygiene is one of the best ways to keep illness at bay while on a holiday. One can’t possibly be too hungry to use a serving spoon, right?

What to do if norovirus breaks out on your cruise

Not listening to safety drills

A former chef for Carnival Cruise Line and Royal Caribbean said failing to listen during safety drills was the most annoying thing passengers did.

You don’t want to annoy the ship’s chef do you? Your meals for the rest of the journey depend on the chef! You may have complete trust in the captain for a safe journey but safety drills works best when everyone participates.

In 2012 Seabourn Cruise Line kicked an elderly couple off the ship when they failed to show up at the drill, “despite multiple explicit warnings and personal communication by ship’s officers”, according to the line’s statement.

Messy eating

“Younger [passengers] usually take food and beverages to their cabins, leaving a trail of crumbs and debris along the way,” said Aida Carvahlo, a former human-resources manager for MSC Cruises, Viking Cruises, and Holland America Line. “After eating, they leave plates and glasses through the hallways of cabins. Housekeeping staff sometimes find rotten food under beds.”

There’s no need to be Hansel and Gretel while you’re on a ship. Just ask the friendly crew for directions! Also, no food under the beds please.

Acting in a way they wouldn’t at home

“They behave in a way they would never do at home,” said a Royal Caribbean first officer. “Like would you ever call 911 if the internet does not work or your toilet does not flush?”

Remember, no one likes the boy who cried wolf. Guest services are always there and ready to help. Unless, it is an actual emergency of course.

Visiting the dining room right before it closes

Going to the dining room just before it closes is the most annoying passenger behaviour, said a hostess for Carnival.

Hunger pangs always come at the most inconvenient of times don’t they? Make it a quick one if you really have to, but it’s the perfect excuse to check out other dining options on board, why pass it up!