Captain Hans Oostrijk served as Marachaussee 2 nd class in the military service with Koninklijke Marechausse. He was the Forwarding and Travel Department Manager of Phs. Van Ommeren N.V. Then he worked for Saybolt (Genova, Nederland , International) where he spent most of his career life and was consistently promoted through merits. He first held the position Station Manager wherein he specialization lies on crude oil handling. Then he became the Shift Leader and his major responsibility is special crude handling, loading and discharging. In this job he was involved in marine terminal operations in Europe and North Africa .

He also carried out several international Marine Terminal Management jobs in former Soviet Union such as Odessa , Moscow , and St. Petersburg . His main task is to comprehensively train the employees in marine terminals, crude oil handling, loading and discharging. He worked with the project United Nations Oil for Food in Iraq , wherein he intensely worked on the monitoring of crude oil shipments, inspection of vessels and shore side as well as preparation of documents such as Bill of Lading. He was promoted as General Manager of their Batumi office in Georgia . Then he transferred to Petro Survey B.V. as the Marine Superintendent.