(CNN) — There are few more aspirational travel experiences than a six-month vacation that hits upward of 30 countries.
Sure, the first round-the-world sailing trip back in 1521 didn't go as planned -- legendary Portuguese explorer Ferdinand Magellan died, along with 50 of his crew during the 1,082-day voyage.
Thankfully, today's global journeys are infinitely safer and more comfortable.
In fact, on many ships, you'd be forgiven for thinking you've checked into a five-star hotel suite, such are the levels of luxury on offer.
All the options below declare themselves as world cruises, though what defines a world cruise provokes considerable debate -- a number of companies offer extensive trips that don't fully circumnavigate the globe.
Nonetheless these journeys frequently sell out months, if not years, in advance, so it's worth planning ahead of time. Here are five of them:
1. Silversea, Silver Whisper
Silversea Whisper's two-bedroom Owner's Suite.
Silversea sits at the top tier of the luxury cruise market.
The brand's 115-day world cruise on the Silver Whisper leaves Fort Lauderdale in Florida and finishes in Venice, Italy, via the Panama Canal.
It offers no fewer than 51 ports in 31 countries, including 18 nights in port.
The two-bedroom Owner's Suite goes for $201,250 per person.
The price includes Relais & Chateaux restaurants, butler service, unlimited shore excursions, all liquor and beverages, pre-paid gratuities, Wi-Fi and first-class air travel.
The best part?
A maximum of 382 passengers will be on the ship at one time.
2. Cunard, Queen Elizabeth
Cunard was the first to offer a world cruise way back in 1923 aboard the RMS Laconia, a trip that took 130 days.
In 2016, you shave off 10 days on board Queen Elizabeth to and from Southampton with stops en route that include Madeira, Réunion, Namibia and Curacao.
At $194,000, the 1,375-square-foot Grand Suite has a whirlpool bath, private balcony, gourmet dining and entertainment.
Looking for something a bit more modest?
The Queen Elizabeth was built just six years ago with a capacity of 2,068 passengers, meaning there are a wide range of interior and sea-facing cabin options.
3. Crystal Cruises, Crystal Serenity
Crystal Serenity's Penthouse Suite.
A welcome bottle of Cristal sets the tone in the aptly named Crystal Penthouse on board the Serenity as it sets off for a 101-night round trip from San Francisco.
For $199,370 per person you don't get to go all the way around the world, but you do get a good look at Alaska, Asia, Australia and the South Pacific, with overnights including Tokyo, Sydney and Shanghai.
The 1,345-square-foot suite is one of the most spacious at sea, giving you bragging rights over your 1,000 fellow passengers, but butler service also ensures you never need to leave it.
4. Oceania Cruises, Insignia
The Oceania adds 100 days to Jules Verne's classic with its epic "Around the World in 180 days" sailing.
This one takes you to and from Miami along with 820 other passengers.
A number of events are included, from dinners in Hong Kong and Singapore to a Polynesian lunch in Bora Bora and a tour of Hawaii's Hilo Volcano Winery.
Other stops include New Caledonia, Myanmar, Zanzibar and Penang.
When you're not in the 1,000-square-foot Owner's Suite, which goes for $149,999 per person, diversions include a casino and theater for live entertainment and guest lectures.
5. Regent Seven Seas, Navigator
Regent Seven Seas' Navigator holds 820 passengers.
The Master Suite aboard the Seven Seas will lighten your bank account by $162,000 per person, but you do get 128 days and the chance to set foot on six continents along the way.
Highlights include navigating the Panama Canal, French Polynesia, four ports in India and an extensive Mediterranean tour, before finishing with a transatlantic crossing back to Miami.
As with Silversea, the price is all-inclusive and passenger numbers are comparatively low at just 490 guests.
A door-to-door luggage service also allows you to stock up on mementos along the way without having to haul them home.