The calculated distance (air line) between Graaff-Reinet and Whittlesea is approximately 134 miles respectively 216 kilometers.
By car or train, the actual journey to Whittlesea is certainly longer, as only the direct route (as the crow flies) between Graaff-Reinet and Whittlesea has been calculated here.
Air line (approximately)
216 kilometers
117 nautical miles