The calculated distance (air line) between As Samawah and Umm Qaşr is approximately 180 miles respectively 289 kilometers.
By car or train, the actual journey to Umm Qaşr is certainly longer, as only the direct route (as the crow flies) between As Samawah and Umm Qaşr has been calculated here.
Air line (approximately)
289 kilometers
156 nautical miles