Because there is surviving historical record.

The 1600s were not as long ago as you think. People paid taxes. There were financial ledgers, and letters written, and paintings of significant things. And when the navy ordered an expensive warship there was certainly a contract with the shipyard.

It might seem like forever ago, but in the grand scheme it's pretty modern history.

And as well as records of when it was built, also records of how it was lost.