People with tillers generally lash them amidships when they’re anchored or moored in a tideway. It stops the boat surging around and helps her drift clear of any optimists who have brought up closer than you’d have wished. Keeping the stick in the middle also makes a big difference to the folks on the foredeck trying to secure a mooring. If the rudder’s across the stream, the poor souls will be fighting all the way. This is far less obvious on a wheel-steered boat, so make sure the helm is clearly marked and lock it amidships before you call it a day.