BINNENSCHIFFAHRTSKONTOR BECK GMBH.

The flag is celestial blue with a central white diamond bearing a black serifed “B”. Klaus-Michael Schneider saw it as a jack on a Dettmer ship at Billwerder Bucht on 13 April 2007. Information supplied by a DTG captain on 1 April 2009 enabled identification, and Schneider amended his illustration to make the “B” serifed.