This video shows a German tug boat battling 20-foot waves and Beaufort 11 conditions the North Sea.
The vessel wass on the way to rescue bulk carrier Glory Amsterdam.
Emergency teams were unable to prevent 738ft bulk carrier the Glory Amsterdam drifting on to a sandbank off the North Sea island of Langeoog.
Storm Herwart, whose gusts reached 112mph, caused electricity blackouts in hundreds of thousands of homes in the Czech Republic, Austria and other countries.