Or so the (urban) legend goes…
The sallet (also called celata, salade and schaller) was a war helmet that replaced the bascinet in Italy, western and northern Europe and Hungary during the mid-15th century and are an example of the height of armor production before the practice of wearing such items was done in by firearms.
Of interest, the German-style sallet was the model for the World War I Imperial Stahlhelm, and thereby the helmets that followed it all the way down to modern PASGT k-pots.
And here is an old one.
As noted by a Russian website, complete with the standard vodka references:
German sallet raised from the river Vihra (Belarus) at a depth of 3 meters. Fisherman caught in the dragnet. Suggested as a museum for 2 bottles of vodka (5$) a Mstislavsky District Historical and Archaeological Museum.
Later, the fisherman realized that lost a lot from this exchange and tried to return the helmet back, but it was too late. There archaeologists have found perfectly preserved steel armor of the sixteenth century with poddospeshnikom from buffalo leather and brass plates, gloves, arm rest, chainmail. Elements of the linen and leather clothing knight also found. Presumably helmet was lost in 1502.
People say that the fishermen found another and a sword, but sold for 3 bottles of vodka (7$) that any collector.