He was a member of the Royal Institute of Naval Architects (RINA),[1] and he was awarded the Silver Medal of The International Sailing Federation (ISAF).
[3] Also, during the war years, Czesław Marchaj studied philosophy (clandestinely, as higher education was suppressed by occupation authorities) under Władysław Tatarkiewicz.
In 1970 he decided to live in the United Kingdom (which was considered defection by the Polish authorities and resulted in a long-term separation from his family, which was barred from leaving Poland to join him).
[3] In the years 1969–1990, Czesław Marchaj continued research at the University of Southampton[Note 5] and was a visiting lecturer at multiple top-ranking academic institutions.
In 1979, after many boats were sunk with a loss of life in the Admirals Cup regatta Fastnet race Czesław Marchaj was commissioned to investigate the problem of dynamic instability of yachts in foul weather.