Maneuvers in the harbor should always be done with the engine and at low speed, unless there are emergencies such as engine failure or line in the propeller (in this regard, I remind you that all accidents should be promptly reported to the harbormaster’s office, by declaration of extraordinary event, under penalty of, for example, non-recognition of any damages by insurance companies).
Boat with a single propeller: how to maneuver it
For boats with only one engine, usually the smallest, the combination of the propeller and rudder is most important. A good pilot must be fully aware of the effects both have in maneuvering. It should be kept in mind that the propeller, in addition to the main forward or backward thrust, depending on the direction of rotation, also tends to make the boat curve by imparting considerable lateral thrust to it. The rule of thumb is as follows: a right-handed propeller (i.e., one that, looking from the stern, turns clockwise when in forward motion, tends to move the stern to the right if the boat is moving forward and to the left if it is in reverse.
Consequently, if, for example, the helmsman of a hull that has a right-handed propeller holds the rudder exactly in the center, the boat will turn with the bow to the right as soon as the reverse gear is engaged. With a left-handed propeller exactly the opposite happens. Here, then, if you want to start the boat and keep the bow and stern in the same direction, assuming you have a right-handed propeller (moreover, by far the most common), you need to bring the rudder slightly to the right as soon as the reverse gear is engaged. Evolutionary effects are not always harmful, but rather can assist maneuvers to be performed in tight spaces by juggling forward and reverse skillfully. Speaking of the undesirable effects imprinted on the hull, remind all crew that a push given laterally to the boat, such as pushing the bow to move away from the dock, can cause the stern to turn from the opposite side at the same time.
This is all the more true the slower the boat is moving (since at low speed the rudder has very little effect) and the further forward or aft one is. The evolutionary effects of a propeller are, of course, nil in the case of having a single transmission equipped with counter-rotating propellers, or two engines. In the latter case the propellers normally rotate in the opposite direction, and to maneuver one acts inversely on the motors.
