The boat is now tied off to the special floating mooring post that floats up and down with the water level
in the lock. You can clearly see the post on the side of the chamber and the dock line that is looped around it.
Notice the concrete wall directly in front of the boat. The upstream lock gates are much smaller than the
downstream gates which are visible in the distance behind the boat. Panning the camera up will give you
some idea of the height of the lock chamber walls.
At this point, you should sound your horn to let the dockmaster know you are secured.