England’s lifeblood during the Napoleonic Wars was naval stores to keep its fleet at sea. The primary source of those stores was Scandinavia and Russia and the convoys carrying them traveled via the Baltic and North Sea. As we’ve already seen, this area was so vital that England was willing to expand its war with Napoleon to encompass heretofore neutral powers in order to keep this supply line secure.
The route was treacherous. The relatively shallow depth created significant wave action. The North Sea also caught incoming waves from the Atlantic which then collided with other wave action originating in the English Channel. The Baltic, in particular, was narrow. The weather often prevented accurate latitude calculations and longitude calculation, in the era before the chronometer, was decidedly problematic. A gale, from any point of the compass, immediately placed a ship in danger of being driven onto a lee shore.
This was never more clearly demonstrated than on Christmas Eve, 1811.