Suddenly one of the lookouts calls out. There is an large oil slick and some debris in the water! As the ship moves closer everyone on deck can see and smell a very large oil slick. Articles of clothing, pieces of wood, paper are floating on the surface. A sailor uses a hook to snag some of the debris. The items are definitely German!

It is likely that your ship has damaged or sunk a U-Boat, but you can't be certain. Veteran submarine commanders have been known to fake their own sinking by ejecting debris from their boat. Leaving now might allow the U-Boat to escape.

Your captain knows his business. It's obvious that there is a u-boat down there and that it's in trouble. A little patience may pay off. The sub may have to surface because of damage, or it may resume its patrol and give you a new contact. Your ship makes another pass over the oil slick, dropping ten more depth charges. A much larger oil slick appears with much more debris. Eventually your captain decides its time to rejoin the convoy. The crew feels good that they have likely killed a u-boat, but they miss the feeling of certainty of a confirmed sinking.