USA Appeal US25
Interpretation Requested by the New York Yacht Club
Using double rudders in opposition to decrease speed does not break rule 42.1.
Using double rudders in opposition to decrease speed does not break rule 42.1.
Question
It is not unusual to construct boats with two rudders. One common configuration is one rudder on the keel (often called a trim tab) and the principal rudder farther aft. Another common configuration is two rudders side-by-side (such as on multi-hulls and scows). When turned in opposite directions, the two rudders have a braking effect. Does this use of the rudders break rule 42.1?
Answer
No. Rule 42.1 requires a boat to compete “by using only the wind and water to increase, maintain or decrease her speed.” Thus, the question is whether the use of opposed rudders to decrease speed contravenes that requirement.
Sails are intended to transmit power from the wind to give a vessel forward speed. From the earliest days of square riggers, they have also been backed to stop forward motion.
Rudders are intended to transmit power from the flow of water to change the direction of the boat. In the process, drag is increased, and the boat is slowed.
Using opposed rudders to slow a boat departs from regular use only in degree and purpose. It is comparable to backing sails. Such use to slow a boat is not a breach of rule 42.1. Furthermore, the single motion of turning the rudders in opposite directions does not meet the definition of sculling (rule 42.2(d)); and if repeated, rule 42.3(f) explicitly permits a boat to reduce speed by repeatedly moving her helm.
May 1970
It is not unusual to construct boats with two rudders. One common configuration is one rudder on the keel (often called a trim tab) and the principal rudder farther aft. Another common configuration is two rudders side-by-side (such as on multi-hulls and scows). When turned in opposite directions, the two rudders have a braking effect. Does this use of the rudders break rule 42.1?
Answer
No. Rule 42.1 requires a boat to compete “by using only the wind and water to increase, maintain or decrease her speed.” Thus, the question is whether the use of opposed rudders to decrease speed contravenes that requirement.
Sails are intended to transmit power from the wind to give a vessel forward speed. From the earliest days of square riggers, they have also been backed to stop forward motion.
Rudders are intended to transmit power from the flow of water to change the direction of the boat. In the process, drag is increased, and the boat is slowed.
Using opposed rudders to slow a boat departs from regular use only in degree and purpose. It is comparable to backing sails. Such use to slow a boat is not a breach of rule 42.1. Furthermore, the single motion of turning the rudders in opposite directions does not meet the definition of sculling (rule 42.2(d)); and if repeated, rule 42.3(f) explicitly permits a boat to reduce speed by repeatedly moving her helm.
May 1970