Here are images of a couple of Czechoslovakia stamps depicting competitive team rowing.
Eight-man shell and oar, designed by Czech graphic artist Mario Stretti, engraved by Jindra Schmidt (plus some photogravure), and issued on June 15, 1960 to publicize rowing at the 1960 Summer Olympics, which featured seven events, for men only, held on the Lago di Albano, Italy, Scott No. 969.
Eight-man shell, designed by Czech artist Anna Podzemna-Suchardova, engraved by Ladislav Jirka (plus some photogravure), and issued on September 2, 1964 to publicize rowing at the 1964 Summer Olympics, which again featured seven events, for men only, held on the Toda Rowing Course, located on the Arakawa River in Saitama Prefecture near Tokyo, Japan, Scott No. 1261.