House flag of Somtrans
Somtrans is an inland shipping company based in Wijnegen, on the Albert Canal near Antwerp. Quoting the company website:
Shipping company and chartering agency Somtrans N.V. was founded in 1975 in Antwerp by the Somers family. This well-known Antwerp family was active since the middle of the XIXth century in the shipping business with wooden sailingships.
Somtrans engages in chartering and managing inland tankers which transport mineral oils and chemicals all over Europe using inland waters. The firm owns 21 ships (barges) but other vessels belonging to private shipowers sail for them as well.
On the company website, the house flag is rendered as a Spanish-type horizontally divided swallowtail, yellow edged red; in the centre is a green lozenge, somewhat reduced at the bottom, bearing a white serifed initial 'S'.
Photos of barges, such as the Somtrans XI, however, show a traditional, rectangular flag.