Well the article does say that river barges were used, when actually river and coastal barges were used, and quite a high proportion of the barges were the sea-going type used for traffic along places like the Baltic sea coast.   Also, the article doesn't mention the type of Siebel ferry that was so stable it was still being used after the war (about 150 built by September 1940) and was used to transport troops from Sicily to Tunisia.