Skipsvrak mynt - Sør Kina havet rundt 1850

This coin was excavated from an unidentified Shipwreck in the South China Sea. Ship was carrying a large quantity of these Dutch Duit coins that ranged in date from the 1790s to the 1800s. Given that the latest coins were dated mid 1800s you would expect that ship sank around the 1850s. Corrosion and sediment from being underwater over a hundred years.