Unseen by me, two geese slipped into the lock ahead of my big, 17-tonne boat.
Halfway through filling the lock, there's a honk from below. The geese had swum between the steel boat and the brick wall of the lock chamber. The boat is 6½ feet wide (1.95m), the lock 7 feet (2.15m). Not a lot to spare.
I had to hold the boat away from the wall while herding the geese back to the open space ahead of the bow.