Do you think this is a genuine 1600 AD Knight's sword??

[RomaRana]

Originally Posted by Michael Blalock

Not to keep harping on the implausibility of the blade being as old as described, but could a ferrous sword have actually been at the bottom of the Danube river for hundreds of years as described and not rust away?

Not that the sword in question, but yes they are.

Medieval swords are frequently found in rivers. The silt deposits protect them and form an airtight barrier but they look nothing like that sword.

Finds have been made in (just a few of the many):
Neuenburg lake- Oakeshott page 74 -Records Of the Medieval Sword
the River Aa- Oakeshott records page 48
River Thames - Oakeshott records 26 and The Archeology of Weapons 136

River swords have a hard brown patina and are often very corroded.