I took a weeklong cruise with a carry-on and a backpack. Here are 9 things I wish I'd packed and 10 items I'm glad I brought.

One of the best things I packed was a magnet.

The stateroom decks comprised long hallways lined with identical blue doors, so my magnet made it easier to find my cabin.

But I wish I'd downloaded some movies and shows to watch on my phone in my room.

The cruise ship's WiFi wasn't strong enough for me to stream videos.

I was glad I packed sunscreen for long days in the sun.

I enjoyed a few beach days during my cruise, so sunscreen was essential. And I was sure to pack a reef safe brand since I was visiting multiple beaches.

But I should have remembered to bring some aloe vera gel for the day I forgot to lather up.

Aloe vera typically soothes and cools my burns, so next time, I'll pack some in case I forget to apply sunscreen.

I was glad I brought a rash guard to swim in the ocean.

An excursion guide at one of the ports informed me that some beaches in the Caribbean, like Tulum, Mexico, don't allow sunscreen in the ocean to protect wildlife.

But the water was so clear that I wished I had a waterproof case for my phone to take pictures.

As other cruisers snorkeled with phones in hand, I realized I was missing an opportunity to capture ocean life.

This sun hat also came in handy to block the sun.

I don't typically wear my sun hat — especially not in my home city, New York — so the cruise was the perfect occasion to pull it out of my closet.

I wish I'd also brought an adjustable cap for windy days on the top decks when my sun hat wouldn't stay on my head.

Mornings and evenings on the ship's top decks were so windy that I had to leave my hat in my room to avoid chasing it around.

Even though the weather was hot during the day, this sweater was handy for cool, windy nights and mornings.

I ended up wearing my sweater every day during the Caribbean cruise.

But I only packed one pair of pants and had to wear them every night.

In hindsight, I should have packed a couple more pairs of pants. Sweatpants would have been especially useful at night on the outdoor decks.

I should have brought a windbreaker, too, to keep me warmer on the top decks in the morning and at night.

I was often chilly at night in my sweater alone.

I wish I'd brought a bar of detergent to wash my clothes since I packed light, and laundry services on the ship cost extra.

On my cruise, Royal Caribbean's laundry service charged for each article of clothing — $4 a shirt, $9 a dress, and $2 per pair of underwear.

But at least I packed the right shoes.

I packed two pairs of shoes: sneakers for walking and waterproof sandals for the beach and pools.

Thankfully, I also remembered to bring a waist pack to carry a few things when I didn't feel like lugging my backpack around.

A small pack was handy during port stops and while exploring the ship.

I was also glad I brought a digital watch to keep on ship time.

Ship time is the time zone that cruise ships adhere to even when docked at ports in different time zones.

However, I wish I had downloaded guidebooks for the ports I visited to get a better idea of what to do.

My ship stopped in Roatan, Honduras; Costa Maya and Cozumel, Mexico; and Royal Caribbean's private island in the Bahamas, CocoCay.

I wanted to try my best to avoid illness and was glad I packed vitamins ...

I packed vitamins to support my immune system since I was coming in contact with many people.

... and medicine to combat motion sickness, which I experienced frequently.

I always pack Dramamine on my trips to avoid motion sickness.

More than anything, I wish I had earplugs to help me sleep during rough nights at sea, which sounded like thunder in my stateroom.

It was especially loud since I was at the front of the ship, where seasoned cruisers said movement on ships feels the strongest.

Next time, I'll come prepared.