Why a detour on your cruise might be the best part of the trip

Cruising might look like a rigid sequence of ports and departure times, but it's constantly adapting to changes in weather, tides and other curveballs. Sometimes, those delays and diversions lead to unexpected discoveries that are better than the original plan.

On my recent Norway cruise, it had been raining for days, spoiling the view. At the right moment, conditions eased enough to allow a detour into the less-travelled Trollfjord. Passengers abandoned their dinner tables to watch the ship squeeze through the narrow inlet beneath towering cliffs and misty waterfalls. The captain's gift perked everyone up. In the South Shetland Islands, in early November, choppy seas forced our diversion to Yankee Harbour. By coincidence, we arrived just as thousands of penguins were returning to land for the first time in six months. Even the crew, who'd been there hundreds of times, had never witnessed this nest-seeking procession that marks the start of breeding season.

In the Kimberley, dramatically changing tides can provide an entirely different spectacle. My first time at Montgomery Reef was unremarkable because it was submerged by the high tide. When I revisited another year, the tide receded so rapidly that the reef appeared to rise out of the ocean. Water poured off its edges in gushing cascades, exposing turtles, sea snakes and thrashing fish as they tumbled down the sides.