A/R Planes
Questions & Answers:

Q: How can something so small generate enough force to do anything?

A: Remember water is about 500 times more dense than air. Imagine increasing the size of the A/R Planes by 500 and connecting them to an airplane. Surely there would be a noticeable difference.

Q: What about the torque increase as I add more power – how can they offset that?

A: When you increase power  you increase the draw of the prop and the relative water speed. The Planes' effect is directly proportional to the speed of the water flowing over them.  So more power = more Speed = more force from the Planes  it’s kind of self-regulating!

 Q: How much speed will I lose because of increased drag?

 A: Because the planes frontal area is so small we haven’t been able to measure any speed loss. In fact, we have seen the speed INCREASE in some cases, due to the improved Trim angle!

Q: Will there be any effect on my prop?

A: Maybe - In testing, a boat with a very high X dimension, cavitation was so bad on full throttle take-off  - just as it broke over on a plane - we repeatedly had to stop and start over  - mounting the A/R Planes eliminated the problem! The "hard" water drawn over the Planes torque surfaces and directed at the decending  blade was able to overcome the aeration caused by the hull on breakover.  We’ve  often noticed the prop feel more hooked up  (better throttle response) at cruise speeds 40 - 50 mph.  Like we said, Maybe. 

Q: Will there be any effect in turns?

A:  It depends on your boat. One boat we tested with a nose cone and low water pickup would cavitate in a hard left turn as the prop ran in the shadow of the nose cone. The A/R Planes stopped the problem by redirecting the flow to the prop as in the case above. If it turns better in one direction now chances are - it will react the same in both directions with A/R Planes!

Q: How about - time to plane and acceleration?

A: Again, it depends on your boat.  Generally, time to plane will be reduced and minimum planing speed will be lowered by  the improved trim response and increased lift created by the Planes area!

Q: What happens when I suddenly “chop” the power – does the boat turn left?

A: We’ve spent a lot of time testing - making sure the boat does not do anything "stupid when the throttle is suddenly closed. The prop draw represents a large portion of the force generated - the remaining force from boat speed alone does not seem to cause any "strange" behavior beyond what the boat "normally" does under this condition. We have personally "chopped" the throttle at 65 mph in a 22 ft. boat with no hands on the wheel (real close though!) testing for this effect. We wouldn’t recommend throttle chopping at high speed as general practice in any boat. But the point of the exercise is, the Planes don't have a scary or negative effect on handling when the power is cut off.

Q: My boat wants to chine walk will these help?

A: The self righting action of the Planes and the increased trim response may cure the problem but as always it depends on your particular boat.  

Q: What about rough water  will I notice anything?

A: You bet! Much of our testing and development has been done off Long Beach in  chop ranging from 6 inches to 4 feet - sometimes with 4 or 5 feet of swell added for good measure. This is where you will notice a big difference and here’s why.  As we mentioned above - the area of the Planes produces positive or negative lift according to the angle of attack relative to the water’s surface (trim angle). If  that angle is zero (parallel to the water’s surface) no lift is produced - these positive or negative lifting forces are acting behind both the center of gravity and center of lift of the hull - as the hull encounters a wave, the bow is raised -  the angle of attack of the Plane’s  becomes positive and produces lift  (lifting the transom or leveraging the bow down) - until the Planes reach zero angle of attack - as the wave passes the hull’s center of  gravity  the bow drops this results in a negative angle of attack on the planes (pulling down - behind) the transom -  (the hydrodynamic lift of the  hull opposes this ) so the effect is to leverage the bow up. These effects stabilize the pitch axis of the hull while negative dihedral and neutral torque stabilize the roll and yaw axis. The net result of all this is a much safer, more predictable  ride in rough water!  Or - you can go faster!

So let me get this straight – my boat will plane quicker, handle better, maybe go faster, and I might be able to save the price of Trim Tabs and External Steering too?  

Yes!