Choosing a Boat Prop

One of the most important boating decisions you can make is what type of propeller to use for maximum performance. Good performance can mean the difference between faster speeds, and better gas mileage as well as stability so your choice will both save you money, and provide more fun for you and your family. One of the more confusing issues in prop choices is selecting the number of blades. There are good reasons for both the 3 and 4-bladed versions. In order to choose the prop that is right for your boat you need to know what each type does best.

Use

A 3-bladed prop is easier to find. It is the most common type of propeller used on recreational boats. If, for all purposes, a 3-bladed prop will give you the performance you need you'll find it easier to get replacements in a pinch. It is still a good idea to have a spare on hand, even if the prop you use is readily available, however. If you damage a prop in the middle of a lake, river, or ocean it won't matter too much to you if the marina you dock at has another in stock, or not.

Power
One of the biggest reasons to choose 3 or 4 blades depends on the type of power you need for your daily boating. Both props offer better power for separate reasons. A 3-bladed prop is slower, but has a much higher speed at top end RPMs than its counterpart. A 4-bladed prop is excellent for water sport enthusiasts because it has a faster acceleration to get the boat out of the hole and up on plane faster. A 4-blade prop also helps keep the boat on plane at lower speeds and reduces fuel consumption.

Sizes

Since 3-blade props still dominate the market. They have a much wider selection of sizes than 4-blade props. Increasing or decreasing the diameter of your prop will increase or decrease horsepower. Once you determine the best size for your boat, it isn't likely you'll need to keep getting different sizes. If the size you choose is available in a 4-blade prop and that suits your needs you are in luck. If not, you have no choice other than a 3-blade prop and making it work for you.

Location

The bigger the water the more power you need to control your boat. A 4-blade prop has more holding power for strong currents and rough water. If you operate mainly in small, inland lakes, or calm rivers a 3-blade prop provides more than enough stability for your boat. If you go out in coastal, great lake, or ocean water a 4-blade prop is more important for the extra holding power.

Comfort

One final note on the 4-bladed prop vs. a 3-bladed prop: the 4-blade prop gives a smoother ride. It has less ventilation (shaking) in turns, and more effortless thrust. While 4-blades are generally a more sports-minded prop, some cruising enthusiasts are willing to exchange high-end speed for the stability and comfort of a 4-blade propeller.