A new line of science-themed cruises lets passengers stargaze from the open ocean, a unique location far away from city lights.

Princes Cruises and Discovery Channel have created a line of science-themed cruises called "Discovery at Sea." The excursions feature activities like diving with sharks, spending time with exotic wildlife, looking at auroras and stargazing.

Viewing the night sky from a location far away from city lights can be a magical experience, but it usually requires traveling to very remote locations (which, for some people, is part of the fun). But stargazing on a cruise ship is unique, because the vessel can travel to locations completely devoid of light pollution, and yet viewers are never more than a few steps away from the ship's accommodations

The dining room doors swing open and passengers swarm to the Arctic Buffet, an elegant send-off for those leaving the ship next morning. On offer is the bounty of the north, from reindeer in cream sauce to fresh Greenland halibut, and tables of desserts from cheesecake to cloudberries and cream.

I’m set to dig in when the public-address system interrupts the meal. The captain, we’re told, has spotted the northern lights. After five cloudy nights on our winter voyage, the celebrated aurora borealis that lured passengers to Norway in the dead of winter has finally made an appearance.

What to do? Feast on a gourmet spread or partake in a celestial wonder?

I take a bite of smoked sea trout, and make my choice. Dinner can wait. I head to the windswept deck.

Mother Nature will do one of her best shows in late September and early October, with cruise ships providing views of coastal New England and Canada during the colorful fall foliage display. You'll visit prime leaf-peeping destinations such as Acadia National Park in Bar Harbor, Maine and the narrow channels of Quebec's St. Lawrence Seaway, where you'll see colorful leaves on both sides.

Standing at the bow of one of expedition cruising's hardiest ships as it crunches northward through a carpet of ice, Cecilia Donnelly is almost giggly with excitement. And who can blame her.

The steel-reinforced Fram has just arrived at the edge of the Arctic ice cap, and for the moment, at least, the 67-year-old retiree from Riverside, Calif., can lay claim to being one of the northernmost travelers in the world.

"This is fantastic!" Donnelly gushes as the 318-passenger Fram smashes into a car-length ice chunk, sending a shudder through the vessel. "In all my dreams, I never thought I would make it to the edge of the North Pole."

Fantastic, indeed. And an increasingly sought after experience. A growing number of adventurous travelers are signing up for expedition cruises to the realm of ice and polar bears at the top of the planet, prompting expedition cruise operators to offer an ever larger array of Arctic itineraries.

Locals will tell you the Cayman Islands offer the best scuba diving in the Caribbean. Given the triumvirate of islands boasts a unique dive site for every single day of the year – and this isn’t just marketing speak – it’s easy to believe them.

Already a go-to destination for stingray spotting and dramatic drop-offs, this British Overseas Territory also offers some superb wreck dives within a pirate’s ahoy from the shore. The Caymans’ vibrant reefs are also something of a success story. With the Caribbean thought to have lost a staggering 80 percent of its coral in recent years, largely due to the effects of global warming, a 2013 study found Cayman coral health had bounced back to levels not seen since 1999.

While every diver has their favourites, we’ve scoped out seven of our own top spots to strap on a tank and dive in.

Travel bible Lonely Planet has revealed its Ultimate Travelist in a new book, ranking the top 500 sights in the world as chosen by their expert travel correspondents – y’know, the people who actually write those books you desperately reach for in each new city you visit. The definitive list offers many of the expected “must visit” spots spliced in with a few hidden gems.

The Temples of Angkor in Cambodia were the “undisputed champion” to take the crown, beating out our own Great Barrier Reef in second place and Peru’s Machu Picchu in third.

Along with our famed reef, Australia took out two other spots in the top 20. The Twelve Apostles on Victoria’s Great Ocean Road took out 12th place and – in perhaps a surprising entry –  Tasmania’s Museum of Old and New Art took out spot number 20. Lonely Planet says that MONA is “sexy, provocative, disturbing and deeply engaging. Don’t miss it!”

Some adventure travel types may scoff at the idea of getting on a cruise ship, thinking of it as being too conventional. They should get over that. There are places in the world that are best seen and experienced on water, including little-visited emerging destinations. Check out our picks for the 10 best adventure cruises.

Even vacations have goals: On a Caribbean cruise, you want to see beaches. On a European cruise, you want to see museums and historic sites.

Those are easy goals to achieve. But many travelers booking their first Alaskan cruise want to see wildlife, and they wonder how hard it is to ensure they will. After all, beaches, museums and ruins stay put, but whales and bears tend to move around.

So how hard is it? According to cruise experts, it isn’t hard at all.

Hurtigruten will be adding one more ship to its current fleet of 13 with the purchase of a new expedition ship that will temporarily be named MS Norway Explorer.

“The new ship’s maneuverability and optimal size will bring Hurtigruten’s guests even closer to nature,” says CEO Daniel Skjeldam. “We invest in our fleet to ensure that Hurtigruten remains a world leader in sustainable explorer travels along the Norwegian coast and polar destinations as well as enrich our guests’ unique experiences by expanding our service at destinations such as Greenland, Svalbard and Antarctica.”

The ship was built in Portugal in 2009 at the Viana do Castelo shipyard and is now making its way to Scandinavia. The ship will undergo a total reconstruction including adapting for polar waters; upgrading the cabins, suites and public spaces for the 320 passengers; and adjusting the power plants and emissions so as to meet Hurtigruten’s high standards, the ship will then join the fleet along the Norwegian Coastal Voyage route. The new ship will replace the Midnatsol, which will join the MS Fram in Antarctica for the 2016/17 season.