World's longest tours and cruises: Take a longer break after COVID-19 is over

Budget is the only limit to tour length, since bespoke travel companies can put together anything. In 2013, Britain-based Hurlingham Travel Services famously created a two-year tour that took in all 962 World Heritage sites and cost £1million (A$1.7 million).

But even regular organised group tours allow you to pack in amazing destinations over more than just a week or two, with some already revving their engines.

Adventures Overland hopes to depart in September this year from Imphal in eastern India on a 52-day, 16,000-kilometre drive to London via China, Central Asia and Russia.

The company also offers "the biggest, the grandest and the most epic bus journey in the world" between Delhi and London. It follows a similar route over 70 days, with a departure currently scheduled (perhaps improbably) for August 2021.

Intrepid Travel has a 64-day "Africa Encompassed Northbound" open-truck journey with many departure dates in late 2021 and 2022. It takes hardy travellers from Cape Town to Nairobi and includes Okavango Delta and Serengeti safaris, the Victoria Falls, gorilla-spotting in Uganda, and a surely welcome rest on Zanzibar's beaches.

Intrepid ran one of the longest organised tours ever in 2016, an "Ultimate 365-Day Adventure" that took in Asia, Africa, the Americas and Antarctica, and says it will consider running it again.

Contiki is hoping to revive its 82-day "Seven Wonders of the World" tour in 2022 or 2023, which ticks off big bucket-list sights such as the Taj Mahal, Great Wall, Pyramids and Machu Picchu. G Adventures' 65-day "Great South American Journey" already has 2022 departures.

Meanwhile, if you're missing cruising, then there are super-long options on the high seas too. Demand has been extraordinary among recently cruise-starved travellers.

Regent Seven Seas Cruises' 143-night world cruise in 2023 is already sold out, and every cabin on Oceania's ever-popular "Around the World in 180 Days" cruise in 2023 was snapped up within 24 hours in January this year.

The cruise will visit 33 countries, 96 ports and 60 World Heritage Sites. But for some, 180 days simply isn't enough. Oceania says 20 per cent of its world-cruise guests opted to extend their voyage on either side, bumping their journey up to 218 days.

That has Oceania offering the longest cruise by far, but many cruise lines such as Cunard and Crystal Cruises offer world itineraries well over 100 days long, with departures both in early 2022 and 2023. Viking's longest cruise is 138 days from Fort Lauderdale in Florida to Greenwich (London) by way to the Pacific, Australia, Asia and the Mediterranean.

Viking has previously come up with something even more extravagant. In 2019, it launched a 245-day "Ultimate World Cruise" return from Greenwich that was set to cover 55,700 nautical miles and visit 111 ports in 51 countries. It would have bagged a Guinness World Record for the longest continuous passenger cruise but was scuppered in Dubai on day 204 by the COVID-19 outbreak. The company has no current plans for a repeat attempt.

For the moment, Silversea is capturing the headlines with the launch of the first expedition world cruise. The "Unchartered World Tour" departs from the tip of South America in January 2022 and arrives in Norway 167 days later. Along the way, it visits 30 countries, 107 ports and truly remote places including the Antarctic Peninsula, South Shetland, Easter Island, and Svalbard above the Arctic Circle. That should be enough to satisfy anyone's pent-up lust for travel.