Aerial photograph of British light cruiser HMS Undaunted 1914. Image courtesy Naval Intelligence Dept, UK.
- HMS Undaunted leads a flotilla of four destroyers against German torpedo boats S115, S117, S118 and S119 off the Dutch island of Texel. The four German vessels are sunk.
- Allied forces recapture Armentières
- British submarines enter the Baltic Sea for the first time since the beginning of the war
