20 Mind-Blowing Cruise Ship Amenities You Didn't Know Existed (Slideshow)

3D is so twentieth century, which is why numerous ships across numerous cruise lines now offer 4D entertainment, where guests can watch 3D movies while smells are pumped into the theater, squirts of liquid spatter them, and the seats quiver and shake. This feature can be found aboard Carnival (on the Carnival Breeze), Costa (Deliziosa, Diadema, Fascinosa, Favolosa, Serena, and Luminosa), and MSC (Fantasia, Preziosa, Divina, Magnifica, and Splendida). The visuals include a roller coaster simulation as well as numerous animated adventures for younger guests.

As if roller skating, Xbox, ping pong, and basketball don't provide enough in the way of physical fun, Royal Caribbean's bi-level SeaPlex (aboard the Quantum of the Seas and Anthem of the Seas) also offers a bumper car arena. Each of the dozen mini-autos are capable of holding two people, and the best part: none of the old school sparks overhead to exacerbate your fire fears — the last thing you'd want to worry about while floating in the middle of the ocean.

Fine dining at sea is impressive. Putting a whole circus show on a ship is fascinating. But combining the two? Unimaginable. This is exactly what the Norwegian Epic does with its Cirque Dreams & Dinner experience, which places an entire show of hula-hooping, acrobatics, aerialists, and music in a 265-seat theater where waiters are serving dinner and drinks throughout. Dinner and a show is one thing, but basically being part of the production unfolding onstage is beyond impressive.

For more of the best cruise ships for food, click here.

Escape rooms are all the rage right now, with folks lining up and paying money for the opportunity to be locked in a room where they need to solve a series of puzzles using elements of the room in order to escape within a set time limit. Puzzle Break was one of the first companies to offer this experience, and it has since brought its activity to the seas on Royal Caribbean's MS Anthem of the Seas with "Escape from the Future." This activity is complimentary.

Driving a car at 200 mph isn't possible on a cruise ship, but MSC Cruises comes pretty close. The line's Fantasia-class ships (Fantasia, Splendida, Divina, and Preziosa) feature a Formula 1 virtual simulator where kids and adults alike can climb into the driver's seat of a replica racer and feel the bumping, bouncing, and banking as they watch the race unfold on the surrounding screens.

Looking for a sure-fire way to beat the heat? The Norwegian Breakaway, Getaway, and Epic ships contain various ice bars, where the temperature is set to a cool 17 degrees Fahrenheit. It has to be, since the ice block seats, ice-covered bars, and carved-from-ice glasses couldn't survive otherwise. However, so guests don't stick to everything like a scene from A Christmas Story or Dumb & Dumber, the bar provides hooded coats and gloves — although some guests opt to simply (and crazily) drink in their beachwear instead. A $20 entry fee includes two specialty drinks and 45 minutes in the bar. If this seems brief, it won't once you enter the chilly chamber — even the bartenders work in 30 minutes shifts.

For more on ice establishments, click here to read about 13 cool ice hotels and restaurants.

Celebrity Cruises' Lawn Club Grill isn't just a fancy name, the open-air restaurant is actually surrounded by green, growing grass. Each guest aboard the Silhouette and Reflection also have the option to grill their own food to personalized perfection (or can have it grilled for them, because vacation) or order salads, gourmet build-your-own flatbreads, and other eats. The surrounding grass is also ideal for bocce, croquet, or picnics — using baskets, food, and drink that can be ordered onboard.

Thinking of picnicking? Check out these nine tips for a perfect outing.

Looking for the best possible view on a cruise ship? Royal Caribbean puts competitors to shame with its Quantum-level ships (MS Quantum of the Seas, MS Anthem of the Seas, and MS Ovation of the Seas [launching in late 2016]), all of which offer an observation pod that extends from a 135-foot crane arm to lift guests (up to 14 at once) 300 feet above sea level and offer 360-degree views of the sea, the ship, and the ports of call. The 15-minute "North Star" experience is free, except during sunrise and sunset, when it costs extra. Reservations can be made in advance online.

Looking for the best sunset view while dining? Try one of these 50 restaurants.

Here's a real treat for those interested in how cruise ships operate mechanically and how the crew plans and controls their movement. Windstar Cruises have an "Open Bridge" policy, which allows passengers to visit the bridge at any time and chat with the captain and his officers 24/7. Ask about their duties, ask about the navigational instruments, or even go at night and ask about the constellations above — it's your bridge.

Even with hundreds of cruise ships currently in existence, only one offers a planetarium: Cunard's Queen Mary 2. The QM2 has a 473-seat theater with a retractable dome that converts the room into a 150-guest planetarium, which was developed in association with New York's Hayden Planetarium. The shows run four times per day, and the seats are designed to lean back for optimal viewing. The Illuminations theater is located on deck 3, and is also used as a cinema.

Ever feel like your bartender isn't treating you like a human being? On Royal Caribbean's Quantum of the Seas and Anthem of the Seas this is expected, as the Bionic Bar watering hole is staffed by two robot bartenders who mix, shake, and stir custom drinks from liquor bottles hanging from the ceiling. Unfortunately, the barkeeps won't be able to lend an ear and listen to your troubles, but you also won't be able to tick them off with your complicated order either.

Click here for America's 25 best (human) bartenders.

The new Norwegian Escape (launched in the fall of 2015) offers a unique challenge in the form of a ropes course. This top-deck experience involves 99 exhilarating challenges throughout a dizzying construction of beams, platforms, tracks, ladders, and lines. Guests can take a ride on one of five "sky rails" (similar to zip lines; more on that later) or walk one of two six-inch steel planks that extend eight feet over the side of the ship, all while enjoying beautiful views from high atop the 20-deck ship — for free!

Here are 16 things to know about the new Norwegian Escape.

When at sea, cruise ships offer breathtaking views at all times of day, and in all directions. Well, almost all directions. You can look up, you can look all around, but aside from leaning over a railing or balcony (not recommended), you generally can't look directly down. That is, until the Princess Cruises introduced the SeaWalk, a 60-foot-long glass-enclosed walkway that extends in an arc over the side of the ship, on its Regal and Royal ships. Not only does this experience allow for pristine panoramic views, but guests can also look down and see the ocean rushing by 128 feet below the walkway. Obviously at sunset the views are even more remarkable.

Click here to read about celebrity chef Curtis Stone's new Princess Cruises restaurant.

Shooting skeet off the back of cruise ships used to be a standard activity, but for some reason, it no longer exists on any line. (Apparently some people decided bringing guns aboard ships was a bad idea, or something.) But the Royal Princess has come up with a solution: a virtual shooting range. Using laser technology, guests can now have a computerized mechanism launch the clay pigeons on a screen and fire at them using an electronic gun. Kind of like Nintendo's Duck Hunt, but a lot more advanced (and with a lot less dog laughter).

Ever want to try skydiving, but have a fear of heights? As long as you don't also have a fear of cruises, you're in luck: All three of Royal Caribbean's Quantum-level ships (MS Quantum of the Seas, MS Anthem of the Seas, and MS Ovation of the Seas [launching in late 2016]) feature RipCord by iFLY, a skydiving simulator. Simply suit up in a jumpsuit and hop into the 23-foot-tall vertical wind tunnel, and upward-moving air will lift you up to mimic the feeling of skydiving — while never rising more than 10 or 12 feet off of the ground. This two-minute-long activity is complimentary, and reservations can be made online prior to the cruise.

Looking for another thrill-seeking activity? Check out the 10 craziest things to do in Las Vegas.

The heat and steam provided by saunas are said to assist in overall physical health and wellness, but apparently the same philosophy can be applied to the cold. Thus, Viking Cruises offers a "Snow Grotto" where the air is chilled below freezing and snowflakes gently fall from the ceiling. After enjoying this frosty retreat, guests can slip over to the Viking Star's sauna, thermal pool, hot tub, heated loungers, and therapeutic showers.

Similar question to the skydiving simulator: Ever want to try surfing, but have a fear of big waves? (Or sharks?) Royal Caribbean has you covered on almost all of its ships. On the Freedom, Independence, Liberty, Allure, Oasis, Navigator, Voyager, Anthem, and Quantum of the Seas, guests can grab a board and hang ten on the FlowRider — which mimics the surfing experience by continuously pumping water upward at high speeds over a stationary surface. Still hesitant? Try boogie boarding on the FlowRider instead. Either way, don't eat the wave; patrons of the Wipeout Bar will be watching.

If you're anything like me, my condolences your beer of choice is usually a local one. But what exactly qualifies as "local" on a cruise ship? For AIDA Cruises this is a simple question, because the AIDAblu, AIDAsol, AIDAmar, and AIDAstella all brew their own beer in 265-gallon copper tanks aboard each of the ships. The beers are brewed with seawater (purified and desalinated, of course) and can be enjoyed in one of the onboard beer halls and beer gardens. Guests can even sign up for a brewing workshop and receive a "brewing diploma" after its successful completion.

Click here for a list of the best craft breweries in America.

Roller coasters don't exist on cruise ships (yet...), but Disney created a water slide that provides a similar experience. Called the "AquaDuck," the 765-foot-long slide features turns, drops, and g-forces that mimic the feeling of riding a rollercoaster, but with guest riding on a tube instead. The ride even has an uphill portion, where guests are propelled by high-power water jets. Two ships, the Disney Dream and Disney Fantasy, offer this activity, which also provide some great views of the surrounding area as one turn of the slide protrudes 12 feet off the side of the ship and 150 feet above the ocean. The Disney Magic, Norwegian Getaway, Norwegian Breakaway, MSC Preziosa, and Carnival Sunshine also feature especially notable slides.

Looking for more on Disney? See the 10 best restaurants in Disney World's Magic Kingdom here.

Looking for a mild thrill, but also a way to quickly get across the ship? Well then Royal Caribbean (these people again?!) has just the thing: an intra-ship zip line. Guests can strap into a harness nine decks above the top of the ship and zoom across 82 feet of either the Oasis of the Seas or Allure of the Seas in a matter of seconds. As is the case with most Royal Caribbean activities, there is no charge to ride.