The challenge with the Atomic 4 is to create a prop with the correct diameter and pitch combination to make the most of the engine's direct drive in forward and 1.3:1 gear reduction in reverse. We also want to keep the prop's drag under sail at an acceptable level for cruising and casual racing sailors.

The prop is 12" diameter. It is molded around a bronze hub from the same plastic as a bowling ball. The unique properties of the plastic allow it to flex under different circumstances to just the pitch you want. At cruising speed the prop remains at its at rest pitch of 7" for relaxed performance. At higher speeds the blades flex just a bit and change to a 6" pitch. This allows the engine to run at greater RPM than a 7" pitch would. At higher RPM the engine can achieve its full 30 horsepower rating. In reverse, the prop flexes more, creating an 11" pitch to accommodate the 1.3:1 gear reduction ratio.

We surveyed 96 sailors with Atomic 4's who replaced their bronze props with the Atomic 4 PerfectPitch prop. Here are the results:

How does the PerfectPitch compare with bronze:
                            Better Same Worse
In Forward:           90%   10%    0%
In Reverse:           96%   3%      1%

The company that had these props manufactured has long gone out of business and the props themselves have changed hands more than once. The props show signs of shop wear from moving from company to company.

We found these on Canada's east coast all thrown into a large box. The company that had inherited them did not know what to do with them. We've sorted through them and will provide the best of the bunch to you when you order. Be aware, they do have small dings and scratches, but this will not effect performance.