Zaporozhye Lock is the Deepest on Dnieper River, Ukraine The Viking River Cruise passed through the Zaporozhye lock, the deepest of the five locks as our ship made its way down the Dnieper River. This was the third lock and the last we'd see operate during the day. Kherson would be the next port, followed by transit into the Black Sea. A lock is a device that raises and lowers boats between different river levels. The Mikhail entered the lock during lunchtime and passengers either rushed outside to take photographs or stayed in the glass-enclosed Kiev Restaurant to watch this unique sight.