What does the term 'pitch' refer to in relation to boat propellers?

The term 'pitch' in relation to boat propellers refers to the distance traveled through water in one complete revolution of the propeller. This measurement indicates how effectively the propeller converts rotational motion into thrust and is typically expressed in inches. For example, if a propeller has a pitch of 20 inches, it means that theoretically, the boat would move forward 20 inches for each full revolution of the propeller, assuming no slip occurs.

Understanding pitch is crucial for determining the suitability of a propeller for a particular vessel and engine combination, as it affects the vessel’s speed, efficiency, and performance. A propeller with a pitch that is too high may overload the engine, while one that is too low may cause the vessel to operate inefficiently and fail to reach its optimal speed. This concept is fundamental in selecting the right propeller to match the operational characteristics needed for various marine activities.