The calculated distance (air line) between Oktyabr’skoye and Mykolayiv is approximately 155 miles respectively 250 kilometers.
By car or train, the actual journey to Mykolayiv is certainly longer, as only the direct route (as the crow flies) between Oktyabr’skoye and Mykolayiv has been calculated here.
Air line (approximately)
250 kilometers
135 nautical miles