Abstract: Self steering apparatus for a boat comprising a motion transfer apparatus for converting pivotal movement of a wind vane into rotational movement of a rudder. The latter is located in a support which is pivotable about the fore and aft axis of the boat. A rotatable connection is provided between a control arm arranged for movement with the vane and a rudder arm arranged for movement with the rudder, such that, when movement of the vane is initiated, there is resultant movement of the rudder arm about the fore and aft axis with movement of the rudder about its axis, and subsequent movement by the water of the rudder support about the fore and aft axis, and movement of the control arm is effected on initial movement of the rudder about its axis but does not result from movement of the rudder support about the fore and aft axis. Lines transmit movement of the rudder support about the fore and aft axis to the main rudder or tiller of the boat.