This column goes behind the scenes of one of the most powerful developments in the history of performance boating. Done right, hydrodynamic steps have proved a game-changer. Unfortunately, how and why they work is often misunderstood and rarely fully capitalized on.
While Fountain Powerboats didn’t invent hydrodynamic steps, few could argue against the idea that we brought the technology to the forefront of what is now considered standard equipment on outboard and sterndrive performance boats.
What makes steps work? How were they developed? Where are they placed for maximum effectiveness? How much speed do you gain? What about handling?
For me, all those questions add up to a $20 million answer. Why so much? Because that’s what I invested in more than 20 years of research and development.
Where We Started
Although I didn’t realize it at the time, my early years spent skiing and barefooting on the Tar River in North Carolina taught me invaluable lessons about hydrodynamics. Ever curious, I was continually tweaking the bottoms of my skis. When it was just my toes and the water, I’d make little adjustments and marvel at the differences that merely changing the angle of my feet would make.
Next in my evolution of understanding speed on the water were the years I spent racing tunnel outboards. As part of the vaunted Team Mercury, and as the Formula 1 world champion in 1976, I can’t account for all the hours that Bill Seebold, Earl Bentz and I spent testing ideas.
An F1 raceboat is one of the most sophisticated racing machines in the world. Measuring less than 20 feet, these guided missiles weigh approximately 850 pounds and are capable of speeds exceeding 140 mph. The boats pull astronaut-level g-force in the turns. Driver ability and setup are critical. The difference between winning and losing can come from moving a battery or trim pump a half-inch up, back or sideways.
Finally, when we started Fountain Powerboats 40 years ago, I incorporated many of the design elements I learned blowing everyone away on the river in my Allison Craft. Darris Allison was way ahead of his time. Two features set his boats apart: a pad keel and a notched transom. The pad keel gave the fast vee-bottoms a stable surface to ride on. Putting a notch in the transom allowed elevated drive heights.
Think about running along the beach in ankle-deep versus knee-deep water. The technology Allison developed, and we refined, is still present in every Fountain powerboat.
Stepping Up
In the mid-1990s, my plant manager, Jim Caldwell, suggested adding a step to our notch transom pad keel vee-bottom design. I’d met Caldwell racing tunnel outboards. You didn’t have to spend more than 10 minutes with him to realize that he was driven, determined, wildly innovative and Mensa smart when it came to making a boat run fast.
We selected the Fountain 24 Competition Series as the first test boat. Doing R&D on a smaller boat helped minimize costs in early development. From the start, the step showed promise. Top speed was up, but more important, the boat accelerated better and was more efficient in the midrange. Encouraged by the possibilities, we started developing the technology across the entire line, and I went to work developing and fine-tuning what would turn out to be a performance breakthrough.
For the next three years, we tested almost daily. The goal was simple: get the boat to run level with the least amount of wetted surface possible. Leveraging a boat with positive trim for a bow-up ride attitude sacrifices efficiency. Running negative trim to keep the bow down increases the wetted surface and, subsequently, the drag.
From day one, it was a matter of feel, and trial and error. Minor changes were made as we progressed. With each new test session, we’d alter the angle of attack or change the distance between the steps. At times it just took adding or subtracting glass. When major surgery was needed, we’d cut out entire sections of the bottom, then glass the corrected step back into place. Ultimately, we’d make changes in the mold.
I spared no expense in R&D because I wanted every advantage possible on the racecourse. Once the design was race-tested, we’d incorporate it in our high-performance sportboats, fishboats and cruisers.
Right Company, Right Time
I believe there’s more speed in the bottom of a boat than in the engine compartment. To that end, Fountain Powerboats was uniquely qualified to lead the way in the development of hydrodynamic steps. Our on-the-water facility along the Pamlico River in North Carolina made testing easy. And we had added motivation because racing, speed records and dominance in fishing tournaments were always the heart and soul of our marketing campaign.
Every boat at Fountain goes out the door with a comprehensive performance report. Consequently, over time, we built a massive database that documented improvements and recorded when we’d gone too far. Every boat was part of an ongoing test program. We never stopped developing, and during the past 40 years have tried every combination possible under the sun.
Did it work? Our list of speed records, world championships and tournament records speaks for itself.
The Bottom Line
Hydrodynamic steps have had a dramatic impact on performance. I can’t stress enough, however, that for us performance has always been an entire package that includes the notched transom, pad keel, hydrodynamic steps, drive heights, propellers and gear ratios.
The best way I can describe high-performance hull design is to think of it as a bowl of soup: all kinds of ingredients blended into one gourmet masterpiece. When a boat is perfectly balanced and rides true, it’s faster and more fuel-efficient. It planes easier, accelerates quicker and is easier to drive.
My goal from day one was to build the world’s fastest, safest, smoothest and best-handling boats. Mission accomplished, and hydrodynamic steps are a key reason why.
This article originally appeared in the December 2019 issue.
