The calculated distance (air line) between Yuen Long Kau Hui and Sai Kung is approximately 16 miles respectively 25 kilometers.
By car or train, the actual journey to Sai Kung is certainly longer, as only the direct route (as the crow flies) between Yuen Long Kau Hui and Sai Kung has been calculated here.
Air line (approximately)
25 kilometers
14 nautical miles