PROPULSION, DIRECTIONAL ORGANS AND MANOEUVRING

The propulsion of a boat can be both sail and mechanical. While in sail propulsion the thrust, i.e. the force that moves the boat, is generated by the action of the wind on the sails, in mechanical propulsion the thrust can be generated by propellers and jets.
The rudder enables the 'steering' of a boat and allows it, as they say, to 'pull' to starboard and port. In other words, the rudder allows the direction of a boat to change from a straight motion to a curvilinear motion to starboard or port.
The main parts of a rudder are the head and the blade. The rudder can rotate around its axis, also known as the 'core'. The upper part of the axis is called the 'head'. On the head, the tiller can be inserted, with which the rudder can be manually manoeuvred. The rudder can also be manoeuvred by means of special controls and deflections, which make up what is called the 'ice' and which are operated by the rudder wheel. The rear part of the blade is called the 'back'.
Rudders can be ordinary, compensated and semi-compensated. They are ordinary when the surface of the blade is abaft, i.e. behind, the axis of rotation. They are compensated when a large surface of the blade is forward, i.e. in front, of the axis of rotation. They are semi-compensated when only a small part of the blade is forward of the axis of rotation. The latter two types reduce the effort required to manoeuvre the rudder.
The action of the rudder produces two effects.
The main effect is the rotation of the hull around the axis of the pivot point. The bow, i.e. the front part of the boat, will be pointing inwards, while the stern, i.e. the rear part, will be pointing outwards.
The secondary effect is a braking effect, but also a heeling outwards and an increase in the dive of the bow.
In the braking effect, the loss of speed is greater the wider the angle of the tiller, i.e. the angle the rudder forms with respect to the boat's keel. Typically, the action of the rudder becomes very braking when it is inclined at an angle greater than 30 or 40 degrees. A rudder is said to be at the 'band' when its inclination is maximum.
To steer means to act on the propulsion and steering components in such a way as to steer a boat safely.