It must have been a bummer for the sailmakers, smiths, carpenters, barrel-makers, and painters – not to mention the navy and the king – when the great Swedish warship Vasa went down in Stockholm’s harbor 20 minutes into her maiden voyage in 1628. Hundreds of people spent two years constructing a great warship with 64 cannons on two decks, fitting it out with painted and gilded wooden carvings. And it sank. How embarrassing.
But the Vasa was raised in 1964 and you can see it in the excellent purpose-built Vasa Museum in Stockholm. It’s a wonderful place with lots of interactive displays about all aspects of the Vasa story: technology, physics, history, biology, chemistry, from why it has built and why it sank, to the lives of those who worked and died on the ship, to how it was recovered and preserved. Great stuff.
Lorna of Arabia 
So why did it sink??
Bad design. Big cannons on two decks, and not enough weight below the waterline. A light wind was enough to make it capsize. The builders had concerns but the king was pushing to get the ship finished and off to the war in Poland so they went ahead with the plan. There was an investigation afterward that exonerated the captain.