I've worked on cruise ships for 7 years. Here are 9 things passengers should pack and 9 they shouldn't.

• I've worked on ships for seven years, so I know what travelers should and shouldn't pack.
• Bring sunscreen and hats to protect yourself from the sun.

Even though seven days of cruising may sound like a dream, many people don't know what to bring for the unique traveling experience.

I've worked on cruise ships for seven years, so I've become quite good at packing for my time on board.

Whether you're bringing 70-pound luggage or a backpack, here are the things you should and shouldn't pack:

Always make sure to pack sunscreen

Bringing UV protection may seem obvious, but the sun in most cruise-friendly places can be very harsh and may have you burning in no time.

If you forget sunscreen, you'll have to buy it on board or in a port, where it'll likely be a lot more expensive.

Sea-sickness pills can help with nausea

Cruises usually have sea-sickness pills available on board, but after too much partying and some swaying seas at 2 a.m., you'll be happy to have your own stash in your stateroom.

Many cruises have a formal night, so make sure you pack appropriate attire if you want to participate

While participating in formal night is optional, many cruisers aren't even aware that it's on the itinerary.

Whether you choose a gown, a tux, or a simple dress, it's always nice to hit the town all dressed up.

Lanyards with a cardholder make it easy to keep your key on you

When you step onto the ship, your room key becomes an important companion. It's how you pay for everything on board, it opens your door, and it's required to get on and off the boat in ports.

They're small and easy to lose, so make your life easier by bringing a lanyard with a holder for the key.

Walking shoes are important on land and at sea

When people imagine cruise footwear, they usually think of sandals. But ships nowadays are massive, and walking back and forth can add up to a good number of steps. So you should make sure you have a comfortable pair of shoes.

Also, many shore excursions require sneakers, depending on the type of adventure.

Make sure you have enough clean underwear

There are no self-service laundromats on most cruise ships, so usually, the only laundry option is to send away your clothes for dry cleaning, which is an additional charge.

To save money, make sure you pack enough essentials, such as undergarments, to last you throughout your stay.

You can pack your own wine, but don't forget to bring a corkscrew

You can bring a certain amount of wine on board, though the amount varies. But once you carry it on the ship, you'll typically be charged a corkage to open it.

Save yourself the money by bringing a corkscrew to open it yourself.

Protect yourself from the sun with headgear

The sun on cruises is a lot stronger than most people are used to, especially on Caribbean trips. I've seen the tops of many heads get red an hour into a tour or beach day.

So make a conscious decision to protect your head with a hat or scarf.

Bring some sweaters to stay cozy on the ship

It may seem odd to pack sweaters for a Caribbean adventure, but the ship itself is heavily air-conditioned inside and runs very cold.

Some cruise ships even have ice-skating rinks, and you'll be freezing watching an ice show without a sweater.

On the other hand, superhigh heels aren't worth the risk

I'm not saying don't bring heels — I want you to look fabulous — but excessively high-heeled shoes on a swaying ship can lead to injury. I speak from personal experience.

Don't bother trying to pack alcohol in shampoo bottles

It's a common ruse for cruisers to attempt to sneak alcohol onto a ship in inconspicuous containers, like empty shampoo or mouthwash bottles.

Besides the soapy taste the booze takes on, security is trained to look out for these tricks and will confiscate the liquor.

Irons are prohibited on board

While heated hair appliances are OK, clothing irons are forbidden on most cruises since they're a fire hazard.

If you pack one, your bag will be flagged and likely confiscated by security until you depart from the cruise.

While they may be romantic, real candles are a massive fire hazard

Like irons, candles are a huge fire risk, so they're absolutely prohibited.

If you're looking for a way to set the mood for your romantic hot-tub date, bring battery-operated candles instead.

Even if they're legal in certain places, drugs aren't allowed on board

Even though some drugs are legal in certain states, there is a zero-tolerance policy on cruise ships.

This also includes prohibited substances cruisers may find in port.

Trying to bring a gun may land you in legal trouble

This might seem obvious, but I've seen passengers try to bring firearms with them multiple times.

The gun will be confiscated, and you and your entire party will be denied boarding. Plus, you may face legal issues afterward.

Skip packing beach towels, and use the ones provided to you

Save some room and weight in your luggage by not packing beach towels.

The ship has multiple stations to provide you with towels for your pool or beach day.

You most likely won't be allowed to fly your drone on the ship

Many cruisers are looking to get a million-dollar drone shot of the ship with a beautiful backdrop, but these devices aren't allowed to be flown on board.

While you can bring your drone to use off the ship, most ports don't allow flying them without permits. So save the space and leave it at home.

Cruisers aren't allowed to bring fresh produce

Save yourself the headache and leave your fresh fruit at home.

Because of federal agricultural regulations, guests aren't allowed to bring produce on or off the ship at any point. The cruise will have all the fruits and veggies you need.