What Should You Consider Before Buying a Boat Propeller
Typically, boating enthusiasts forget to consider the importance of their boat’s propeller. The propeller is the direct connection between the horsepower and the water. Therefore, when shopping for a propeller for your boat, make sure you make all the necessary considerations.
Getting the Right Shape and Size
Propellers can be purchased in an entire range of shapes and sizes. In terms of sizes, diameter and pitch are two crucial measurements that must be taken. First off, be sure that the propeller pitch fits the engine manufacturers recommended WOT (wide open throttle) range. This means it should be possible for the throttle to be fully advanced when you turn the minimum rpm for which the engine was created. As the pitch of a propeller goes up, there is an accompanying in crease in weight or limit for the engine to raise its rpm’s. A 50-horsepower engine may only be capable of turning a 15-pitch propeller, while a 750 horsepower offshore race engine can turn over 30 inches of pitch.
Checking the Diameter
Diameter can also be a factor in terms of rpm capabilities and some other boat and hull personalities.
Another factor can impact impact rpm capabilities and certain other boat and hull personalities, is diameter. Several of the diameter options are already predetermined for the user by the propeller maker. This usually works great for non-high performance applications. However, overall performance can be dramatically improved by fine tuning diameter. Reducing diameter will often lower rpm, and the same is true the other way around. Adjustments in diameter adjustments change the hulls’ running attitude too. Changing the diameter is not always needed though as the stock diameters may be matched to different propeller types.
Number of Blades
In theory, less blades create faster speeds. This is based on the premise that more blades create more metal in the water, thereby translating to more drag. However, if you have an inefficiently running boat, more blades can give the boat more capability to “hook up” and improve its performance thoughout the torque band. The specific boat application will help the determine how many blades will give the best results.
Choosing the right boat propeller can indeed be intimidating. Seeking the help of a trained professional is the best way to optimize your boat set-up. Most will be glad to help by sharing their knowledge on the subject. It’s probably not even necessary to meet them in person. Just participate in online forums and get tips from there.
Lastly, the most critical starting point is being familiar with your engine or engines capabilities. When you have this out of the way, the engine package can be safe from damage that may arise from improper rpm related to propping. From here, you can decide if you would like to upgrade its performance.