You're Being Too Loud, Whisper!

Published: 10/23/13 at 09:30am

By now you may have heard the rumors and they are true, Max-Prop now makes a five blade propeller. We call it the Whisper.

Max-Prop five blade Whisper

The Max-Prop five bladed "Whisper".

A Weight Lifter

The Max-Prop Whisper uses five blades to provide ultra quiet operation and impressive thrust. The resulting improved powering performance is especially noticeable when powering against heavy wind and seas. In fact when in forward the Whisper will offer 96% of the efficiency of a fixed blade propeller of the same diameter and pitch. That 4% loss in power can usually be eliminated by precisely matching the pitch of the Whisper to fit the boat engine combination. What is pitch you may ask? Read our “What is Propeller Pitch” blog we wrote a while back. Once you have a basic understanding of what is involved with setting the pitch don’t hesitate to give us a call! When comparing this five bladed propeller to a three bladed propeller you’ll see that the Whisper will maintain boat speed about 15% better when powering into heavy wind and seas.

Back It Up!

As with all of the propellers that Max-Prop makes this one also has outstanding reverse. The Whisper provides 80% more power than a comparable fixed blade propeller. The key is that this propeller utilizes the same leading edge in the forward as it does in reverse giving the propeller the same thrust in both directions, and thus dramatically improving control and power in reverse.

Smooth As A Babies Bottom

The five blade design also provides for a substantial noise and vibration reduction in all conditions resulting in a smoother ride. You see with more blades they act as a balance. Similar to if you were add counter weights to your wheel when you notice a lot of vibration coming from your wheel.

Drag Is Such A Drag

You’ll hear a lot of sailors who race love Max-Props because they have such low drag. And with the Whisper there is no exception. While under sail all five of the blades on the Whisper feather to a low drag position. Under sail the Whisper will increase sailing speed by about 15%, the largest difference being noticed when sailing in light air. When sailing with a fixed blade propeller the vessel has to overcome the fixed blade drag, making the boat much slower.

Max-Prop Whisper in feathered position

Whisper blades feathered.

Pitch adjustment screws

Pitch adjustment screws.

It’s Easy

The Whisper is based on the “Easy” design, so it ships fully assembled, making installation and pitch changes simple and fast. Just slip the hub on the shaft, thread and tighten the nut, thread the two lock screws for the nut, install the zinc anode with three screws, and voila it’s installed!

The pitch is adjustable 2 degree increments, providing the ability to fine tune the loading of the engine. Moreover, pitch adjustment can be done in the water as the propeller does not need to be disassembled to change the pitch.

The Whisper is designed for large vessels with heavy displacement, or applications with very fast shaft RPMs to quiet down the rotation.

Fred Hutchison