Tanker (1970)

A young married couple, professional, intelligent and without inhibitions. Peter, an economist, Helga, a secretary at a financial broker. When Helga's boss is offered old tankers, the clever couple decides to get involved in the business. The plan is bound to fail, because knowledge and the courage to take risks are not enough. To rake in money, above all, a lot of money is needed.

Unfortunately the movie Tanker is not yet available on HBO Max.