This Germans news show report from 1953 shows the inventor of the “Wasserläufer” riding his hydrofoil in the river Isar in Munich!
Translation of the news report:
“And another patent for advanced mobility. The Wasserläufer a simple machine based on complicated calculations. You push water and move. The father and driver of this machine is a engineer in Bavaria. Up and down, up and down without any rudder or paddle wheel. Everything self powered with muscle power and ingenuity.”