U-boat

Gasoline rationing was instituted: There was no lack of product from the oil fields, it was simply being torpedoed by U-boats, causing severe shortages along the East Coast.

More than 500 of the ship's crew died when it was attacked by a German U-boat in October 1914.

Guy Ritchie’s latest follows a group of British special forces who took on German U-boats during World War II — and helped inspire James Bond.

That included staffing her post as the news came in that a convoy escorted by her future husband’s ship, the destroyer HMS Oribi, had been attacked by a U-boat wolf pack.

Members of the German naval staff were calling for a return to unrestricted submarine warfare—allowing U-boat captains to sink Allied shipping in international waters without warning.