First-time cruisers often don't know what questions they should ask about their cruise because it's all so new and overwhelming. Then they get onboard and are stymied over the tiniest of details.

To save you some heartache, we read through Cruise Critic's Ask a Cruise Question forum to find some of those questions that are often overlooked by newbies but obvious to longtime cruisers. Here, we present 10 questions you never even thought to ask -- and our expert answers, of course.

1. Do I need to pay for drinkable water?

The tap water onboard cruise ships is perfectly potable -- whether from the sink in your bathroom or the dispensers in the buffet. Cruise ships have onboard water desalination systems that purify and safely store water. You can request ice from your cabin steward or waiter if you prefer to drink cold water.

However, some cruisers don't like the particular taste of the onboard water (just as some people don't like the tap water at home), and prefer to drink bottled water, either still or sparkling. Cruise ships carry an abundance of bottled water, but unless you're on a ship with an all-inclusive beverage policy or have pre-purchased a drinks package, you'll need to pay extra. Fees vary, though a bottle of generic-brand still water will be cheaper than a name-brand like Pellegrino.

2. How do I keep track of my cruise card?

Most cruise lines print each passenger a plastic wallet-sized card to be used as an onboard ID, room key and onboard credit card. You need to have it with you at all times -- but you're likely not carrying around your purse or wallet as you do at home. So how do you keep track of it, especially when you're heading to the pool in your swimsuit or to yoga class at the gym?

Many cruisers just stash the cards in their pockets. Some prefer to wear them on lanyards around their necks (useful for kids), while others stash them in a small bag or clutch they carry with them. Or, you can carry it around in your hand and hope you don't leave it on a buffet table. Some cruise lines, often higher-end ones, will give you a two-pocket mini-wallet that fits your cruise card and a fold-up map of the ship.

It's also wise to pick a place in your stateroom to stash your cruise card, so you're not hunting for it every time you want to leave the cabin.

 Messaging apps can help you keep in touch (Photo: tolotola/Shutterstock)

3. How do I find people in my travel party on the ship?

As a society used to texting and calling people, it's daunting to imagine trying to find a friend or family member on a mega-ship when you can't use your cellphone. Cruisers and cruise lines have come up with several solutions for this problem.

If your cruise ship offers free unlimited internet, or everyone buys a purchasable plan, or your cruise line offers an app that allows onboard texting, you can use the ship's Wi-Fi to find your friends via your mobile phone.

Otherwise, you need to resort to more 20th-century habits. Agree on meeting times and places at breakfast, so if you split up, you know where to find each other later in the day. Use a whiteboard on your cabin door or notepads in your room to alert your travel party where on the ship you're headed. Some families use walkie-talkies, but they don't always work so well onboard.

4. What do I do if I don't like the people at my assigned table?

Several cruise lines still offer the choice of eating at the same time every night -- but that means eating at the same table, often with tablemates the cruise line picks for you. Tables for two can be hard to come by, and unless your travel party is big enough, you likely will be sitting with strangers. But what if you don't get on?

You can avoid the situation entirely by choosing flexible dining, where you can arrive at any time during restaurant open hours. Even if you can't score a table for two, you'll eat with different parties every night so if you have an incompatible group one night, you likely won't dine with them again. If you're allocated assigned dining and can't abide your tablemates, speak to the maitre d' and request a change. He will do his best to reassign you, but might need to switch your assigned dining time or change you to flexible dining.

Otherwise, you can skip the main dining room and take all your meals in the buffet, a specialty restaurant or your cabin with room service.

Cruise ships loan out beach towels for water-base shore excursions or shore-side relaxation (Photo:CAN BALCIOGLU/Shutterstock)

5. Do I need to pack beach towels?

Like hotels, cruise ships provide towels for in-cabin use -- but what about by the pool or for water-based shore excursions? Happily, you don't need to waste luggage space with beach towels. Cruise ships provide them, either in your cabin or by the pool. You can take these towels with you when you leave the ship to hit the beach or go on a snorkeling excursion.

There's just one catch: You have to keep track of your towel. Since it's so easy to leave a towel behind, some cruise ships charge for lost towels. When you need a new one, you can trade a wet towel for a fresh one on the pool deck or with your stateroom attendant. Just make sure you always have one per person in your travel party.

6. How do you nab a spot by the pool when it's crowded?

Every cruiser has visions of a relaxing afternoon by the pool -- until you show up and find the Lido Deck packed with wall-to-wall sunbathers.

If you want a spot, don't be shy. Seek out empty loungers, and if you can't find two together, see if you can't move two closer or politely inquire if someone could move one chair over to accommodate you. If you see a chair with belongings on it but no people, ask neighboring sunbathers if someone has been using a chair. If no one's been seen, the stuff likely belongs to a chair hog; you're OK to move the items if they haven't been there for a half-hour.

If you can't get a spot by the pool, there is usually plenty of extra lounge space on the upper decks. You might have to settle for some loungers forward or aft, out of eyeshot of the pool deck happenings, but these can also be quieter and more pleasant. To get a primo spot, you need to be lucky, or get there early in the morning and stay in your spot all day.

7. Can I do laundry onboard?

Daywear, swimwear, eveningwear -- it's hard to pack light for a cruise. But, do you have options if you want to cut down on the bags you carry? Yes.

Oceangoing cruise lines always offer laundry service for a fee. You give your clothes to your room steward in a bag with an order form, and they're returned laundered and neatly folded. However, these options can be expensive. Select ships offer self-service launderettes, where you can wash, dry and iron your clothes, either for free or for a small fee as in any laundromat. This option is more affordable, but takes time out of your vacation.

You can also rinse out clothes in your cabin sink and hang them to dry in the shower or elsewhere in your room. Most cruise ships have clotheslines built into the bathroom, but then you have to move half-dry items every time you need to shower. Perhaps the best option is to pack strategically, bringing items you can wear more than once, and reserve onboard laundry as a last resort.

Dining onboard Grand Princess (Photo: Princess Cruises)

8. How much food can I order in the main dining room?

It's hard to go hungry on a cruise ship. Restaurant waiters have been known to urge passengers to order more courses or try another dessert. But just how much food can you order in the included-in-your-fare main dining room?

You can basically order as much as you want. You can order two (or more!) entrees, order a half portion of an entree as an appetizer, make a meal out of several starters, try out multiple desserts, mix the sides of one dish with the main protein from the other -- if you can think up the combination, wait staff will generally oblige. If you don't like a dish, you can send it back and order something else; if you're still hungry after your main course, you could order another entree before dessert.

Please be mindful of waste, however, and only order what you reasonably think you can eat. It's fine to try out a few dishes and not finish them, but don't order six appetizers and only take a bite out of each.

9. Do I have to dress up?

Cruise lines have relaxed their dress codes over the years, and no one is ever forced to dress up, though you might not be permitted into the main dining room if you choose to dress down on a dressy night. Some lines still have a formal or formal optional night; others have a no jeans rule in the dining room. Norwegian Cruise Line never has a dress code on any night.

Mainstream cruise lines will have one or more casual dinner options, such as a buffet restaurant, where you don't need to dress for dinner. However, the formal night menu in the main dining room might feature primo dishes like lobster that you will miss out on if you choose to dine elsewhere. Whether you feel uncomfortable going to the evening show in jeans while other passengers are dressed to the nines is really up to you.

Some high-end lines do have a requirement that passengers adhere to the stated dress code in all public spaces after 6 p.m., meaning if you don't wish to throw on at least trousers and a nice top, you might be relegated to room service and in-cabin movies all evening.

Passport and Travel Documents (Photo: Alexey Stiop/Shutterstock)

10. What do I do with my passport during my cruise?

While you will need (or want to have) a passport for many, but not all cruises, you mainly need it to check in for your sailing. The exceptions are cruises to certain destinations where you're required to show your passport to clear customs. But in most destinations, you don't need to carry it with you when you go ashore, and it's not worth risking your passport getting lost or stolen.

On some cruises, the purser will hold on to all passenger passports for the duration of the sailing. If this is not the case on your vacation, the best thing to do is put your passport in your in-cabin safe and leave it there until you're ready to disembark. (And always check the safe when you're packing at the end of the cruise!) If you want to have a record of it in the unlikely case that you get left behind in port, consider carrying a photocopy rather than the actual book.