The rule of thumb is to retract, however don't fully retract if you are in traffic or pulling up to dock and are powering slowly you lose tracking ability in these conditions. Also, if powering in seas and or windy conditions leave the keel down or you risk rounding-up or sliding sideways and possibly laying flat. If you can fully steer the boat using motor only your boat becomes a powerboat and the need to lower the keel is reduced. Novelman
