Page:Small-boat sailing; an explanation of the management of small yachts, half-decked and open sailing-boats of various rigs; sailing on sea and on river; cruising, etc (IA smallboatsailing01knig).pdf/42

 should do—slight weather helm, he counteracts this, and keeps her on her course, by putting his tiller a little over to the weather side of the boat, and so pushing the rudder over to the lee side.

A reference to Fig. 9 will make clear the action of the rudder. Here the rudder has been pushed over to the port, or left, side of the vessel. The resistance of the water flowing by it acts in the direction of the arrow, at right angles to the rudder's surface. This force is resolvable into two other forces, one pushing the boat backwards, and the other driving the boat's stern sideways to starboard—that is, to the right, and consequently turning the bow to port. But the axis on which the boat turns when the rudder is placed at an angle with the keel is always considerably forward of the centre of the boat, so that the stern of the boat is moved sideways a greater distance than the bow. This will be apparent on referring to Fig. 9, in which X is the centre of rotation, while the dotted line shows the movement the boat has made in response to her tiller. It is important to remember this fact when steering close to a boat or other object; for when one puts over the helm in order to keep one's bow clear of the object, one is very apt by that very action to bring one's stern into collision with it.

Some boats do not readily obey their rudders,