No one wants to ruin their heavily planned cruise holiday, and certainly not end up on the sidelines as the ship sails away, so there’s some things to note before you start warming up your sea legs.

According to CN Traveler, there’s 10 things you should absolutely avoid if you plan on getting onboard your cruise adventure – and staying there until the end!

And if you’ve taken our hot tips to selling cruise better, and sold a few of these bad boys, it’s worth running through these with your clients.

1. Not Having the Paperwork

According to CN Traveler, cruise ships are leaving your country’s waters and going overseas (haha – get it?)

Yep, so that means you’re going to need a passport – preferably yours ?

As CN Traveler notes, if you don’t produce one at check-in, you won’t be allowed entry. It’s not so much getting kicked off, as not being allowed on. And this guy should know!

2. You’re Banned from a Country

As CN Traveler writes, you might’ve been banned from a country and oh no, the cruise ship actually stops there.

If that country’s immigration alerts the cruise line, it will toss you from the ship prior to arrival in the destination.

3. Miss the Muster Drill

What the heck is a muster drill, we asked ourselves when reading the CN Traveler article!?

Well, unlike dozing through the safety demonstration onboard a flight, a muster drill is apparently the one thing on a cruise where attendance in mandatory.

Per CN Traveler, back in 2012—shortly after the Costa Concordia disaster in Italy—both Holland America and Seabourn had highly publicised incidents where they booted passengers off the ship because they skipped this important drill.

4. Practice Poor Time Management

While this woman might’ve tried swimming after her cruise ship when it left without her, the main lesson was that if you’re not on time, the ship will leave without you.

Per CN Traveler, cruise employees call this the Run of Shame, and it happens when passengers visit a port, lose track of time, and miss the ship’s debarkation. Then your choices are either meet it at the next port or go home.

5. Bringing Drugs Onboard

It might seem obvious, but past incidents have shown that some people still need to be seriously reminded – don’t bring illegal drugs on board!

Just piquing the drug dogs’ interest (which often come aboard at a new port) is enough to have cruise lines throw you overboard, not to mention a little stay in local government “care” should they actually find drugs on you.

And in the US, search and seizure laws don’t extend to ships either, according to CN Traveler. Just refuse to have your room searched, and cruise lines will kick you off as well.

6. Throwing Anything Overboard

Tossing anything overboard—food, cigarette butts, a spouse (just kidding, please don’t) – well, it’ll get you the boot off your beloved ship.

Per CN Traveler, one poor Aussie reportedly had his cruise ended by simply flicking a cigarette butt off the deck in Bali.

7. Impersonating Crew

So this is one we didn’t know, but also seems really weird. You can pop on a sailors hat and dance around the cruise ship disco, but posing as a a crew member will apparently get you kicked off in an instant.

8. Getting Ill

Getting sick on ships is pretty shippy (sorry about all the puns!) but if a cruise ship finds out you’re the one to start a highly contagious onboard plague, seeya later!

Per CN Traveler, cruise lines will also drop passengers that feel gravely ill, more for their own safety than that of other passengers.

9. Fighting

Alright, seems obvious – but some might think a bit of a biff might just get you a slap on the wrist.

Apparently not.

Per CN Traveler, cruise lines “don’t even care if you’re an F-list reality TV “star,” as Bad Girls Club’s Judy Jai learned in 2015 when she was thrown off a cruise in Jamaica after getting into a fight with her cabin-mate AC Style. Or Trace Adkins, who left a ship and checked into rehab after getting into a fight with a passenger who was apparently butchering his songs at karaoke.”

Wow, those are serious. Basically don’t fight, and if you’re feeling fired up, walk away.

10. Chucking a Tantrum, or Otherwise Being Verbally Abusive

So it’s not just fighting that’ll see you left at the nearest port – causing commotion with words will also land you a ticket back to shore.

As CN Traveler writes, you can “just ask Foxy Brown, who back in 2011 got so enraged when the onboard salon couldn’t accommodate her manicure—after she showed up three hours late—that she was booted when the boat docked in the Cayman Islands”.

Some people just shouldn’t travel! For the full article, check out CN Traveler.