What a wonderful sight? The article below tells you all.

Photo credited to IWM

  When the people of the town of Hastings awoke one morning to see one of the Kaiser’s U-boats on their beach, it caused some shock. Thousands of visitors flocked to see the beached submarine. The Admiralty allowed the town clerk to charge a fee for people to climb on the deck. Two members of the coastguard were tasked with showing important visitors around inside the submarine. The visits were curtailed when both men became severely ill, they both died shortly after. It was a mystery which killed the men at the time and so all trips into the sub were stopped, it was later discovered that chlorine gas which had been escaping from SM U-118′s batteries had caused severe abscesses on the lungs and brains of the unfortunate men.

For full story see Submarine Ashore at Hastings