He was born in Prague. In 1968 he was a crew member of the Czechoslovak boat which finished fifth in the eight event. Four years later he won the bronze medal with the Czechoslovak boat in the coxed four competition. At the 1976 Games he was part of the Czechoslovak boat which finished fourth in the coxed four contest.[1]
Mareček chaired the Czech Rowing Union from 1988 to 1996, and also served on the Czech Olympic Committee. He died, aged 76, on 25 January 2020.[2]