The calculated distance (air line) between Dawei and Damnoen Saduak is approximately 125 miles respectively 200 kilometers.
By car or train, the actual journey to Damnoen Saduak is certainly longer, as only the direct route (as the crow flies) between Dawei and Damnoen Saduak has been calculated here.
Air line (approximately)
200 kilometers
108 nautical miles