The Vasa sank 1,300 metres from its own quay

The Vasa sailed one thousand three hundred metres and went to the bottom. It was 10 August 1628, in Stockholm harbour, and that warship — sixty-four bronze cannon spread over two gun decks — was the most expensive thing Gustavus Adolphus, king of Sweden, ever ordered. A gust of wind heeled her over, water poured in through the gun ports, left open for the farewell salute, and she sank with some thirty people aboard, in full view of the whole city.

The bad part is that they already knew. Weeks earlier, tied up at the quay, Admiral Klas Fleming ordered the stability test of the day: thirty men running from side to side to make the hull roll. On the third run the ship was leaning so far that Fleming called a halt. He cancelled nothing. The king was away on campaign waiting for his ship, and nobody wanted to be the one to write and tell him that the second gun deck, added mid-build on his own orders, had turned it into a tall, narrow wardrobe.

Baltic mud turned out to be a preservative: cold water, low salt and no shipworm to eat the timber. In 1961, after 333 years down there, they raised her whole, with 98% of her original oak. Today the Vasa is Sweden's most visited museum: over a million people a year pay to see the ship that could not manage one thousand three hundred metres.