The calculated distance (air line) between Mykolayiv and Chornomors’k is approximately 79 miles respectively 127 kilometers.
By car or train, the actual journey to Chornomors’k is certainly longer, as only the direct route (as the crow flies) between Mykolayiv and Chornomors’k has been calculated here.
Air line (approximately)
127 kilometers
68 nautical miles