After the USA effectively threatened war, Germany halted its U-boat campaign against Allied shipping. Or rather it limited the U-boats to attacks using cruiser rules, whereby they had to stop and search Allied ships for contraband before sinking them. This put U-boats at a severe disadvantage, as it left them vulnerable to attack by guns concealed on Allied merchantmen.
More recently the U-boat campaign has been escalated. This is at the urging of Falkenhayn, who sees the U-boat as a vital tool for use against Britain. The U-boats are still not free to attack enemy civilian ships on sight; instead they are only allowed to attack Allied ships that have been fitted with guns. However, as many Allied merchantmen and liners now have some guns fitted, this gives U-boats a pretty free hand.
Today the UB-29 is patrolling in the Channel when it spots the SS Sussex, a French-flagged ship carrying passengers between Folkestone and Dieppe. Perhaps it is mistaken for a warship or perhaps the UB-29’s crew assume that it probably has some kind of armaments fitted. Either way a torpedo is fired. The Sussex is hit. The crippled ship does not sink, but 50 people onboard lose their lives, some when their lifeboats capsize.
SS Sussex survivors (East Sussex County Council Libraries on Flickr)