N.V. STOOMVAART MAATSCHAPPIJ "OOSTZEE".

The flag is white with a red-black-red triband in the upper hoist quarter, representing Amsterdam, and a black O in the lower fly. The yellow funnel bears the same triband. Sources vary in band widths: black often looks wider, though it is also shown narrower on the funnel. Captain Eldert Dobbenga’s sketchbook calls the flag the company, Oostzee or Vinke flag.