I have sets of bouys and markings from 1924 for Denmark, Great Britain, Ireland, France, North-America, Netherland, Belgium, Germany, Sweden, Norway and Russia.
https://www.dropbox.com/s/goekxzeesh..._1924.jpg?dl=0
https://www.dropbox.com/s/4y4lezoxid..._1924.jpg?dl=0
I dont know whether the bouys where changed between ww1 and 1924, there is a note on the Norwegian bouys and marks about an update from a previous system in 1914.