My friend Catriona and I are well-practised travelling companions, with a history in backpacking and a shared talent for tent-pitching, but finding ourselves on a luxury cruise was without precedent. However, the best way to explore Antarctica is by water, so we signed up to join the Silver Endeavour on its inaugural voyage to the White Continent. As a new, comparatively small and state-of-the-art ship, it can fly through the waves at 19 knots, cut through metre-thick ice and turn on a six-pence, meaning it can go further inland, or down narrower channels, than most. It is named after Captain Cook’s HMS Endeavour, though on this occasion, it was not carrying the pigs, poultry, two greyhounds and a milking goat that the great seaman took with him in 1768. Instead,…