If a seven-night cruise doesn't seem long enough, would 100 nights of lavish galas, hobnobbing with interesting fellow passengers and visits to faraway lands be more your style? If so, it's time to get a world cruise on your 2019 or 2020 travel calendar.

Around-the-world voyages have been around since Cunard's RMS Laconia sailed the first one in 1922. Yet they remain popular today, thanks to continuing itinerary innovations by the cruise lines and modern technology that makes it easier than ever to stay in touch when you're spending 100-plus days at sea. We've seen trends toward even longer sailings (Viking is running the industry's lengthiest-ever continuous world cruise at 244 nights in 2019), and some -- like Cunard and Princess -- have even been known to run two or more a year.

A few things to note: Many world cruises don't sail fully around the world, though they do offer a chance to see a varied portfolio of diverse cultures all in one sailing. Also, if you can't commit to a full world cruise, you can often book one "segment" of the voyage, ranging from a week to more than a month. World cruises typically begin in January and end in April or May, but some lines change it up with departures in other seasons.

Whether you want to dream big or live large, here's the rundown of 2019 and 2020 world cruises.

2019 World Cruises

2020 World Cruises

Crystal Symphony in Hong Kong at night

Fred. Olsen

The Trip: This global cruise on Boudicca, which sails for 168 nights round trip from Dover, England, in 2019, is the longest-ever world cruise for the line. For this trip, the ship heads southwest from Europe, doing some island-hopping in spots like the Canary Islands and Cape Verde, before traveling about Africa. Then it's off to Asia and Australia, before looping back through the Middle East, with a Suez Canal transit. The voyage continues into the Mediterranean before Boudicca heads back north to Dover, where the cruise ends on March 19.

Departure Date: October 3, 2019

Itinerary Segments: Dover to Tenerife (Canary Islands), 7 nights; Tenerife to Cape Town, 21 nights; Cape Town to Victoria (Seychelles), 14 nights; Victoria to Phuket, 14 nights; Phuket to Bali, 14 nights; Bali to Cairns, 28 nights; Cairns to Bali, 14 nights; Bali to Colombo (Sri Lanka), 14 nights; Colombo to Dubai, 14 nights; Dubai to Limassol (Cyprus), 14 nights; Limassol to Dover, 14 nights

Price: Full world cruise fares range from £14,999 to £30,599 per person; segments start from £699, double occupancy.

Princess Cruises

Sea Princess

The Trip: Princess runs a second 106-night world cruise in 2019 aboard Sea Princess, with a more unusual itinerary and schedule that embarks round trip from Sydney in May (with additional launch points available round trip from Brisbane or Auckland). Expect nearly 40 ports of call in more than 30 countries throughout Australia, Asia, the Middle East (with a Suez Canal crossing), the Mediterranean, Northern Europe, Canada, the Eastern U.S., the Panama Canal, Central and South America, the South Pacific and New Zealand. Sea Princess returns to Sydney on August 29.

Departure Date: May 14, 2019

Itinerary Segments: Sydney to Dubai, 22 nights; Sydney to London, 56 nights; Sydney to New York, 68 nights; Brisbane to London, 54 nights; Auckland to London, 60 nights; Dubai to London, 34 nights; London to Auckland, 46 nights; London to Brisbane, 52 nights;  London to Sydney, 50 nights; London to New York, 12 nights; New York to Sydney, 38 nights

Price: Full world cruise fares range from $17,709 to $28,509 per person; segments start from $3,979, double occupancy.

Viking Ocean Cruises

Viking Sun - August

The Trip: Viking Sun will sail the longest-ever continuous "Ultimate World Cruise " featuring an incredibly lengthy 244-night itinerary that makes a full circumnavigation of the globe. The entire eight-month journey, sailing round trip from London, will visit 59 countries on six continents, with an included-in-the-fare excursion in every port; 22 ports will feature overnight calls. Two shorter itinerary variations -- including a 126-night segment from London to L.A., or a 118-night voyage from L.A. to London -- are also available. From London, the full voyage explores Northern Europe, Iceland and Greenland, continuing on to Canada, the Northeast U.S., and Bermuda. The Caribbean, South America and California follow, before making way to the South Pacific and Australia/New Zealand. Finally, the ship heads to Asia, the Middle East and the Mediterranean. The sailing ends in London on May 2, 2020

Departure Date: August 31, 2019

Itinerary Segments: London to Los Angeles, 126 nights; Los Angeles to London, 118 nights

Price: Full world cruise fares range from $92,990 to $269,990 per person; segment fares start from $45,995 per person, based on double occupancy.

Crystal Symphony in Cape Town

2020 World Cruises

Costa Cruises

The Trip: Costa runs its annual world voyage aboard Costa Deliziosa in 2020. The 112-night voyage embarks round trip from Venice in January, with more than 40 stops scheduled in Italy, Greece, France, Spain, Barbados, Aruba, Panama, Ecuador, Peru, Chile, the Pitcairn Islands, French Polynesia, Tonga, New Zealand, Australia, Papua New Guinea, Japan, South Korea, China, Hong Kong, Vietnam, Singapore, Malaysia, Sri Lanka, India, Oman, Jordan and Israel. The ship returns to Venice on April 26, 2020.

Departure Date: January 5, 2020

Itinerary Segments: Rome to Venice, 108 nights; Barcelona to Venice, 106 nights

Price: Full world cruise fares range from $14,779 to $34,259 per person; segments start from $14,719, double occupancy.

Cruise & Maritime Voyages

The Trip: The line's third consecutive "Grand Round the World Cruise" on Columbus, this 120-night adventure sails round trip from London (at Tilbury) on January 6, 2020, spanning 27 countries in five continents, including a transit of the Panama and Suez canals. Port calls unfold in the Caribbean, South America, South Pacific, Australia/New Zealand, Asia, the Middle East and Europe. This sailing ends in London on May 5, 2020; there is also an option to sail round trip from Amsterdam, embarking on January 7, 2020, and returning May 6, 2020.

Departure Date: January 6, 2020

Itinerary Segments: Segments have not yet been made available for bookings.

Price: Full world cruise fares range from $12,699 to $43,179 per person.

Crystal Cruises

The Trip: Crystal Serenity's "Epic Empires & Idyllic Isles" is a 105-night voyage (and the 25th world cruise for the line) that calls nearly exclusively on ports in the Southern Hemisphere. The itinerary, spanning 47 cities in 23 countries, begins in Miami on January 6, 2020. The ship will head south to Colombia before transiting the Panama Canal and cruising the coast of Central America and Mexico. There's a pit stop in L.A. (a secondary world cruise launch point), before making way for the South Pacific to visit the Marquesas Islands, the Society Islands, the Cook Islands, Tonga and Fiji; it's then on to New Zealand and Australia. Asia follows, with Indonesia, Singapore, Malaysia, Thailand, Sri Lanka and India, before dipping into the Middle East at Oman, Israel and Jordan (with a Suez Canal transit). The sailing rounds out at some Greek Islands and along the Italian coast, before disembarkation in Rome on April 21.

Departure Date: January 6, 2020

Itinerary Segments: Miami to Los Angeles, 15 nights; Los Angeles to Papeete, 13 nights; Papeete to Auckland, 15 nights; Auckland to Sydney, 13 nights; Sydney to Singapore, 17 nights; Singapore to Mumbai, 14 nights; Mumbai to Rome, 18 nights

Price: Full world cruise fares range from $30,447 to $202,099 per person; segment fares begin at $4,499 per person for a suite.

Cunard Line

The Trip: Sail east from New York on a 113-night world cruise (Cunard's only for 2020) aboard Queen Mary 2. The itinerary takes passengers through Europe, Africa, Australia, Asia and the Middle East (with a Suez Canal crossing). A pickup for a shorter 99-night world cruise from Southampton (also disembarking in Southampton) is also available on this route. During the 26-country itinerary, passengers can anticipate highlights like overnight stays in Cape Town, Hong Kong and Dubai. QM2 returns to NYC on April 25, 2020.

Departure Date: January 3, 2020

Itinerary Segments: New York to Southampton, 7 nights; New York to Dubai, 27 nights; New York to Hong Kong, 46 nights; Southampton to Singapore, 34 nights; Southampton to Hong Kong, 39 nights; Southampton to Sydney, 56 nights; Southampton to Fremantle, 64 nights; Dubai to Singapore, 14 nights; Dubai to Hong Kong, 19 nights; Dubai to Sydney, 36 nights; Dubai to Fremantle, 44 nights; Singapore to Sydney, 22 nights; Singapore to Fremantle, 30 nights; Singapore to Cape Town, 48 nights; Hong Kong to Sydney, 17 nights; Hong Kong to Fremantle, 25 nights; Hong Kong to Cape Town, 43 nights; Hong Kong to Southampton, 60 nights; Sydney to Fremantle, 8 nights; Sydney to Cape Town, 26 nights; Sydney to Southampton, 43 nights; Fremantle to Cape Town, 18 nights; Fremantle to Southampton, 35 nights; Cape Town to Southampton, 17 nights; Cape Town to New York, 24 nights; Southampton to New York, 7 nights

Price: Full world cruise fares range from $18,069 to $183,620 per person; segments start from $1,169, double occupancy.

Holland America Line

The Trip: Holland America's Amsterdam sails a 128-night world voyage round trip from Fort Lauderdale in January 2020. A quick stop in the Caribbean (at Dominica and St. Lucia) is followed up by calls in South America at French Guiana, Brazil, Uruguay, Argentina and Chile, with a rare detour to Antarctica. The ship makes way for several calls throughout the South Pacific, with New Zealand and Australia, before cruising through Asia, with stops scheduled in Indonesia, Singapore, Sri Lanka and the Maldives. Next up is Africa, with the islands of the Seychelles, Mayotte and Madagascar, as well as mainland calls in Kenya, Tanzania, Mozambique, South Africa and Namibia. The ship then hits some remote Atlantic islands, including Saint Helena and Ascension Island, before dipping back into the Caribbean (at Barbados, Guadeloupe and Puerto Rico) and returning to Fort Lauderdale on May 12, 2020.

Departure Date: January 4, 2020

Itinerary Segments: Segments have not yet been posted for booking as of press time.

Price: Full world cruise fares range from $22,799 to $79,990 per person.

MSC Cruises

The Trip: MSC Cruises is following up its successful first (and sold out) world cruise in 2019 with a second one aboard MSC Magnifica in 2020. The voyage embarks from Rome on January 4, 2020, and can also be joined in Genoa, Marseille and Barcelona on January 5, 6 and 7, respectively. The cruise will then take in ports in the Mediterranean, Caribbean, Central and South America, the South Pacific, Australia, Southeast Asia and the Middle East. Plus, eight overnight port calls are featured, with 15 shore excursions included in the fare. The cruise concludes in Genoa on April 30, 2020, after visiting 43 destinations in 23 different countries.

Departure Date: January 4, 2020

Itinerary Segments: Segments are currently unavailable for booking.

Price: Full world cruise fares range from $16,278 to $47,128 per person.

Oceania Cruises

The Trip: In 2020, Insignia sails an "Around the World in 180 Days" voyage, unique in that it crosses the equator four times while visiting a whopping 95 ports -- including a circumnavigation of South America. The 180-night itinerary runs from Miami to San Francisco, from January 8 through July 5; there are also options to extend the voyage to 195 nights to sail round trip back to Miami, or to 200 nights, by sailing on to New York. (Embarkation is also available out of San Francisco on January 26, sailing round trip for 162 nights, or on to Miami for 177 nights or to New York for 182 nights.)

Passengers will start with visits to Key West and Havana, Cuba, heading to Colombia, Central America (including a Panama Canal transit) and Mexico, before hitting up the California coast (and the secondary pickup point in San Francisco). It's then onward for even more Mexico and Central America, before an intensive South American visit. Following a transatlantic crossing, numerous calls in Africa await, before moving on toward an extended stay in Asia, including visits to nine Japanese ports. Russia and Alaska follow up, before the ship winds back down the West Coast to San Francisco.

Departure Date: January 8, 2020

Itinerary Segments: Miami to San Francisco, 18 nights; San Francisco to Santiago, 22 nights; Santiago to Buenos Aires, 16 nights; Buenos Aires to Cape Town, 36 nights; Cape Town to Singapore, 30 nights; Singapore to Hong Kong, 15 nights; Hong Kong to Tokyo, 18 nights; Hong Kong to San Francisco, 43 nights; San Francisco to New York, 20 nights

Price: Full world cruise fares range from $37,499 to $141,499 per person, double occupancy; segments start from $1,999, double occupancy.

P&O Cruises

The Trip: Arcadia embarks on an intrepid 99-night global voyage on January 3, 2020. The ship sets sail from Southampton and travels west, passing through both the Panama and Suez canals, and visiting 27 ports. Highlights include stops in U.S. ports such as San Francisco and Honolulu; explorations of destinations in New Zealand and on the eastern coast of Australia; a good number of Asian points, including stops in China, Sri Lanka and Malaysia; and a dip into the Middle East with Oman and the U.A.E. The monthslong circumnavigation ends in Southampton on April 12.

Departure Date: January 3, 2020

Itinerary Segments: Southampton to Auckland, 42 nights; Southampton to Sydney, 47 nights; Southampton to Brisbane, 49 nights; Southampton to San Francisco, 25 nights; Auckland to Southampton, 57 nights; Sydney to Southampton, 52 nights; Brisbane to Southampton, 50 nights; San Francisco to Hong Kong, 41 nights; San Francisco to Brisbane, 24 nights; San Francisco to Sydney, 22 nights; Sydney to Singapore, 23 nights; Sydney to Hong Kong, 19 nights; Brisbane to Hong Kong, 17 nights; Hong Kong to Dubai, 14 nights; Hong Kong to Southampton, 33 nights; Singapore to Southampton, 29 nights; Dubai to Southampton, 19 nights

Price: Full world cruise fares range from £9,999 to £26,799 per person; segments start at £2,474, double occupancy.

Princess Cruises

The Trip: Princess' 111-night world cruise voyage aboard Pacific Princess sets sail from Fort Lauderdale in January and will visit 42 ports of call. The cruise begins with stops in Aruba followed by a traverse of the Panama Canal and calls in Costa Rica and Mexico. The ship then reaches its second pickup point in Los Angeles, where cruisers have the option to join the world cruise late, on January 20. From there, it's on to Hawaii, French Polynesia, New Zealand, Australia and Asia (with stops in Indonesia, Singapore, Thailand, Sri Lanka and the Maldives), before a dip into Africa, with calls in Tanzania, Madagascar, South Africa, Namibia and more. A transatlantic crossing back to Fort Lauderdale follows, with stops in Brazil and the Caribbean en route, in time for disembarkation on April 26.

Departure Date: January 5, 2020

Itinerary Segments: Ft. Lauderdale to Los Angeles, 15 nights; Los Angeles to Sydney, 29 nights; Los Angeles to Cape Town, 74 nights; Los Angeles to Fort Lauderdale, 96 nights

Price: Full world cruise fares range from $22,999 to $68,999 per person; segments start from $2,449, double occupancy.

Regent Seven Seas Cruises

The Trip: Sail aboard plush Seven Seas Mariner's 131-night world cruise itinerary, running round trip from Miami in January; a second round trip variation on the sailing is available with a pickup in San Francisco on January 24. Taking in 30 countries spread out over six continents (all except Antarctica), passengers will have the opportunity to visit 36 UNESCO World Heritage Sites and to enjoy 13 overnight calls. Bonus: Nearly 400 worldwide shore excursions are included in the upfront rates, as are three exclusive shoreside events in New Zealand, Singapore and Tuscany. The ship returns to Miami on May 17, 2020.

Departure Date: January 6, 2020

Itinerary Segments: Miami to San Francisco, 18 nights; San Francisco to Papeete, 18 nights; Papeete to Sydney, 18 nights; Sydney to Singapore, 18 nights; Singapore to Abu Dhabi, 20 nights; Abu Dhabi to Rome, 21 nights; Rome to Miami, 18 nights; Miami to San Francisco, 18 nights

Price: Full world all-inclusive cruise fares range from $65,999 to $175,999 per person, including airfare; segments start from $11,000, double occupancy.

Seabourn Cruises

The Trip: Seabourn's 146-night world cruise -- its first official world cruise in six years, despite lengthy extended explorations -- departs Miami on January 4, 2020, and will visit 62 ports in 36 countries. Seabourn Sojourn will start by heading south and east, visiting the Caribbean before crossing the Atlantic to Africa, where it will visit ports on the continent's east, south and west coasts. It then sails on to India, Southeast Asia and Indonesia, and finishes up with visits to Australia, the South Pacific and Hawaii. Highlights include 16 overnight calls, 18 additional late-night stays and options for mid-cruise, over-land excursions to places like the Taj Mahal. The cruise ends in San Francisco on May 28, 2020.

Departure Date: January 4, 2020

Itinerary Segments: Miami to Cape Town, 39 nights; Miami to Singapore, 78 nights; Miami to Sydney, 116 nights; Cape Town to Singapore, 39 nights; Cape Town to Sydney, 77 nights; Cape Town to San Francisco, 107 nights; Singapore to Sydney, 38 nights; Singapore to San Francisco, 68 nights; Sydney to San Francisco, 30 nights.

Price: Full world all-inclusive cruise fares range from $65,999 to $142,999 per person, including airfare; segments start from $13,499, double occupancy.

Silversea Cruises

The Trip: Silver Whisper's 2020 world cruise is a 139-night voyage that is causing a buzz for visiting all seven continents, including an expedition experience in the Antarctic (a first during a world cruise for the line), and calls on 62 ports in 32 countries. The ship sails from Fort Lauderdale to the Caribbean and South America, followed by an expedition-style visit to Antarctica. From there, the ship sails around to Chile before voyaging to Easter Island and onto French Polynesia and more South Pacific. Australia and Asia (including Indonesia, Singapore, India and more) follow, before sailing through the Middle East, Mediterranean and Northern Europe to finish up in Amsterdam on May 25, 2020

Departure Date: January 6, 2020

Itinerary Segments: Fort Lauderdale to Buenos Aires, 21 nights; Buenos Aires to Valparaiso, 19 nights; Valparaiso to Papeete, 15 nights; Papeete to Sydney, 18 nights; Sydney to Singapore, 18 nights; Singapore to Mumbai, 11 nights; Mumbai to Rome, 18 nights; Rome to Dublin, 9 nights; Dublin to Amsterdam, 10 nights

Price: Full world cruise fares range from $62,000 to $240,000 per person, based on double occupancy; segments are not yet open for booking.