Most conventional cruise ships head for the busy shores of the Mediterranean during Europe's summer months, but expedition lines tend to prioritise the northern reaches of Europe, Asia and North America at this time of year. The summer thaw means that ships can sail beyond the Arctic Circle to the Svalbard archipelago, one of the best places on earth to see polar bears in the wild. It's also a popular time of year to visit Greenland, Iceland and northern Norway.

In mid- to late August you will find a handful of expedition ships setting off on ambitious Northwest Passage voyages between Greenland or eastern Canada and Alaska, and sometimes the epic Northeast Passage through the Russian Arctic. Look out too for some very special (and very expensive!) voyages to the North Pole itself.

June to August is high season in Alaska, when many of the busier ports can be overrun with cruise ship visitors, but a voyage on a small expedition ship will take you off the beaten track into true wilderness regions that the big ships can't reach. Across the Bering Strait, summer is peak birdwatching season in the Russian Far East, a truly unique cruising destination.

Other summer options include Australia's rugged Kimberley region, with the chance to spot humpback whales in July and August and experience the spectacular King George Falls in full flow during May and June. Our summer is also the best time visit Papua New Guinea, when the weather is cooler and drier.