'However many times it has been done, the act of casting off the warps and letting go one's last hold of the shore at the start of a voyage has about it something solemn and irrevocable, like marriage, for better or for worse.'

Mostly Mischief's ordinary title belies four more extraordinary voyages made by H.W. 'Bill' Tilman covering almost 25,000 miles in both Arctic and Antarctic waters.

The first sees the pilot cutter Mischief retracing the steps of Elizabethan explorer John Davis to the eastern entrance to the Northwest Passage. Tilman and a companion land on the north coast and make the hazardous crossing of Bylot Island while the remainder of the crew make the eventful passage to the southern shore to recover the climbing party. Back in England, Tilman refuses to accept the condemnation of Mischief's surveyor, undertaking costly repairs before heading back to sea for a first encounter with the East Greenland ice.

Between June 1964 and September 1965, Tilman is at sea almost without a break. Two eventful voyages to East Greenland in Mischief provide the entertaining bookends to his account of the five-month voyage in the Southern Ocean as skipper of the schooner Patanela. Tilman had been hand-picked by the expedition leader as the navigator best able to land a team of Australian and New Zealand climbers and scientists on Heard Island, a tiny volcanic speck in the Furious Fifties devoid of safe anchorages and capped by an unclimbed glaciated peak. In a separate account of this successful voyage, Colin Putt describes the expedition as unique—the first ascent of a mountain to start below sea level.