Once a preserve of the rich, today cruising is more affordable and accessible than ever before – in 2015, 23 million people worldwide sailed the high seas. They’re profitable too; according to stastiticbrain.com vacationers spend on average $500 (£405) more a week on a cruise than on any other trips. Whether you’re a seasoned cruiser or you're simply curious about an ocean voyage, take a look at some of the best cruises available in 2017.