JF Ptak Science Books Quick Post
According to the armistice signed on November 11, 1918 (and prior to the Treaty of Versailles which was signed 28 June 1919) in addition to much else Germany agreed to the internment of their High Seas Fleet, surrender 5,000 cannons and 25,000 machine guns and 1,700 aircraft, release all POWs, and deliver all remaining U-Boats, which is the subject of this post.
The subs made their way across the North Sea to the coast of England, near Essex, and were met there by a British force, which then took command of the ships, delivering them to the Port of Harwich. This began on 21 November and continued for a few weeks, resulting in the surrender of 122 subs and associated craft. The image below (from a photo pool, this one associated with the Western Newspaper Union) was made during that time and released on 2 December 1918. It looks as though the German crews were still on board at this point, their own flags still flying prior to being replaced by a white ensign.
Similar scenes took place in France--here is another News Photo Service photograph showing surrendered German subs being taken in France, together with the paper slip that newspapers and other publishers were supposed to use with the image upon publication.