IRTYSH SHIPPING CO.
image by Victor Lomantsov, 09 Sep 2000
Victor Lomantsov saw the I83 flag in magazines of the 1970s and believed it remained in use into the 1990s.
The riverships.ru flag is presumed to be post-Soviet. Its Cyrillic ИРП corresponds to IRP.
Rosanoski considers Mitchell’s funnel logically post-1991. The presumed successor name Irtysh River Co. appears instead to have become Irtysh Shipping Co.