Career
During the 1948 Summer Olympics in Torbay, Jonker helmed the Dragon Joy, with crew members Biem Dudok van Heel and Wim van Duyl, to an 8th place.
During the 1948 Summer Olympics in Torbay, Jonker helmed the Dragon Joy, with crew members Biem Dudok van Heel and Wim van Duyl, to an 8th place.