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Being the designer of Royal Huisman’s 192-foot (58.5-meter) motoryacht Phi carries a fair amount of gravitas and rock-star status. Phi, notable as the longest motoryacht in the world under 500 gross tons, is one of this year’s most talked-about yachts. Dutch designer Cor D. Rover created her distinctive exterior styling, as well as that of her shadow boat built by Alia.

“The owner wanted the exterior to be cobralike and aggressive,” Rover says. “I made a million sketches and went way too far in that direction. He reeled me back in, and thank goodness he did.”

 Cor D. Rover’s team in action.

 Cor D. Rover’s team in action.

Phi’s technically savvy owner commissioned Rover largely based on the designer’s yacht swimming pool design, DEPP, which heats and treats the water when the pool is not in use, reducing the amount of fresh water used overall—and making the pool usable about five minutes after the yacht arrives in port or drops anchor. Rover registered the DEPP patent in 2012, but until Phi, the system had never been incorporated on a yacht.

“The concept is really quite simple,” Rover says. “The pool double-functions as a dump tank, obviating the need for an extra tank to hold the water. It requires no pumping of fresh water. In a nutshell, an inflatable seal in the upper position of the pool, combined with 100 percent topping off with a little extra water and adding a light pressure overload, prevents the sloshing of water, turning the body of water into a solid block of ballast.”

The owner of Phi believed that a pool with the DEPP system also added to the yacht’s stability, and limited overall weight. Saving even more gross tonnage required Rover to consider things as unusual as the air between the fashion plates (the aesthetic side plates connecting the deck overhangs).

Phi’s name derives from phi, the 21st letter of the Greek alphabet. It has been known to symbolize the golden ratio, an ancient mathematical concept. Over the centuries, much lore has built up around the notion of phi representing perfect beauty as uniquely found in nature. It is a cosmic constant found in the shape of hurricanes, elephant tusks, flower petals, the swirls of a nautilus shell, and the Fibonacci sequence—a series of numbers where the next number equals the addition of the previous two numbers.

Rover’s distinctive styling on the 220-foot Benetti Seasense.

Rover’s distinctive styling on the 220-foot Benetti Seasense.

Designing an entire yacht to adhere to the golden ratio is a heady concept, but having had a lifelong interest in the way things work, especially boats, Rover was up for a design challenge. The fourth of six children, Rover was born on his parents’ inland-water barge.

“Perhaps it was the constant smell of water that made me addicted to being in and around the water,” he says, adding that his early ambitions did not include naval architecture. “I was not much interested in learning from books. I never did my homework.”

Instead, as a hands-on learner, he spent all his time making models of airplanes, constructing radio-controlled boats, and building surfboards.

“My passion was figuring out how to make something work,” he says.

He got a degree in mechanical engineering and took extra courses in naval architecture. Rover’s first job out of the university was with Dutch naval architect Frank Mulder. Rover was tasked with doing the construction calculations on John Staluppi’s 133-foot (40.2-meter) Heesen Octopussy, the yacht that was designed to break the 50-knot barrier back in 1988.

“When the ABS Class society does not believe in what you are doing and would not give the yacht a rating for above 27 knots, it was both scary and exciting,” Rover says. “My strength calculations proved to be correct, and the boat was a success and achieved her speed goal.”

The launch of 192-foot Phi at Royal Huisman proved quite a spectator sport.

The launch of 192-foot Phi at Royal Huisman proved quite a spectator sport.

Octopussy topped out at 53.17 knots and, at the time, was the fastest megayacht in the world. In 1992, the next Mulder project for Staluppi, the 116-foot (35.3-meter) Norwegian-built Moonraker, exceeded Octopussy and achieved a maximum speed of 66.7 knots.

Rover worked with Mulder for 11 years. “I learned a tremendous amount from Frank,” he says. “However, in 1997, I felt it was time to become independent and start my own studio. As I did not feel it right to poach any of Frank’s clients, I really started from scratch.”

His first independent designs were for a 40-foot Elling E3 production powerboat that is still in production some 20 years later. In 1998, Rover showed some concept designs at the Monaco Yacht Show; his first custom big-boat client was American businessman Walter Goldstein, for whom he designed the 133-foot (40.5-meter) Mondomarine Blue Belle. Rover then designed another nine yachts with Mondomarine, creating exterior styling and general accommodations plans. Other notable custom yachts from his pen were the 148-foot (45-meter) Hakvoort My Trust and two yachts built at Dutch Yacht Builders (now Acico Yachts): the 154-foot (47-meter) Lady Dee and the 142-foot (43.5-meter) Latitude. In 2017, Rover achieved accolades for the 220-foot (67-meter) Benetti Seasense.

Sketches of cobralike Phi went through many iterations before the owner approved the final design. 

Sketches of cobralike Phi went through many iterations before the owner approved the final design. 

Concurrent with his larger custom commissions, Rover was working on design concepts for the Horizon FD series production yachts.

“In Europe, form usually comes before function,” he says. “In creating my 27-meter pocket superyacht, I worked from the inside out, making it modular, changeable and flexible while maintaining a consistent engineering platform.”

He placed the owner’s stateroom as far forward as aesthetically possible on the main deck, a location that, at the time, was a bit of a novelty. He shopped the design to a few builders at the 2012 Fort Lauderdale International Boat Show.

“John Lu, CEO of Taiwan-based Horizon Yachts, immediately saw great potential for it in the company’s major markets of America and Australia and began production right away,” Rover says. “The Horizon FD series has proven wildly popular. They are producing one boat a month. I am continuing to design new Horizon models. We have a new 125 coming out with drop-down balconies.”

Rover is also involved in a series of motoryachts for Turkish builder Sirena Yachts in the 68- to 88-foot (20- to 27-meter) range. He also designed all models of the Zeelander brand by adding sensuality and speed to the traditional Maine lobster boat. Rover is just as enthusiastic about production boats as he is about big projects like Phi: Creating a series that is aesthetically pleasing, works well and offers larger-yacht amenities is the kind of puzzle he thrives on.

Rover’s exterior styling on Seasense featured an unusually large swimming pool. 

Rover’s exterior styling on Seasense featured an unusually large swimming pool. 

“I really enjoy getting to know our clients in the midrange bracket of yachts,” he says.

During his downtime, Rover is involved in his church. “I belong to a very inclusive and inviting church where all people are welcome,” he says, adding that he helps with outreach programs. “During the workday, I am talking to a billionaire client, and in the evenings, I may be talking with a homeless addict or ex-convict.”

He is quick to add that he is no saint. “I enjoy a good glass of wine and a nice meal, but it is important not to lose sight of living in a world with others,” he says. “I am keenly aware that the welder on his knees in the bilge is equally as important as the big boss next to me who pays the bills.”

It seems that in addition to being adept at executing the golden ratio, Rover is also conversant in the Golden Rule.

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This article was originally published in the Fall 2021 issue.