A wing three–quarter, van der Watt played rugby at the Air Force Gymnasium in Valhalla alongside
Frik du Preez during his military training, before continuing with rugby at Stellenbosch University. He had success against the touring
1969 Wallabies, with two tries for Western Province and a hat–trick for the South African under 23s (Gazelles). This earned him a Springboks call up for their
1969–70 tour of Britain and Ireland, where he played in three of the four Test matches, amongst a total of 17 appearances. He was recalled for the
1971 tour of Australia as a replacement, but didn't feature in any of the internationals. ==Teaching==