Rainer Borkowsky was only 14-years-old, when he claimed the silver medal as the cox in the coxed pairs with Horst Arndt and Moritz von Groddeck at the 1956 Melbourne Olympics. They were, at the time, the reigning West German and European champions and successfully defended both titles in 1957. After von Groddeck left Rudergesellschaft Wiesbaden-Biebrich 1888, and moved to Ratzeburg, Arndt and Borkowsky rowed with coxed fours and eights, and finished third at the German Championships on several occasions.