The calculated distance (air line) between Chornomors’k and Serhiyivka is approximately 23 miles respectively 38 kilometers.
By car or train, the actual journey to Serhiyivka is certainly longer, as only the direct route (as the crow flies) between Chornomors’k and Serhiyivka has been calculated here.
Air line (approximately)
38 kilometers
20 nautical miles