Ships ALGOMA SAULT & WHITEFISH BAY meet below Lock 3, Welland Canal 2023

The cargo ship ALGOMA SAULT is seen upbound on the Welland Canal, Aug 1, 2023, having just passed under the Homer Bridge, and heading towards Lock 3.
Meanwhile, another cargo ship, WHITEFISH BAY, has just been lowered inside Lock 3, and is now departing. The two vessels meet below Lock 3, passing port-to-port, and each continue on their way: ALGOMA SAULT "slides the wall" and heads into Lock 3's open chamber, from which WHITEFISH BAY had just departed.
This is an example of a common and very typical procedure for ships passing each other on the Welland Canal. Sometimes, one of the ships will stop and tie up at the wall, waiting for the other ship to pass. Here, they are doing a "passing entry" procedure, where both ships remain in motion while passing.
Also, note the efficiency here - the lower (north) gates of Lock 3 remain open, after WHITEFISH BAY exits, for the next ship, ALGOMA SAULT to enter; and, the Homer Bridge keeps its deck wings raised until both ships have passed under.