Princeton University Electric Speedboat Team Sets World Record

COURTESY PES

Princeton University Electric Speedboat Team Big Bird during the world speed record runs on Lake Townsend near Greensboro, North Carolina.

Even a broken prop shaft could not slow them down. On October 26, 2023, the 40-plus members of Princeton University’s Electric Speedboat Team (PES) erupted in cheers on a clear, sunny, windless day on the shores of Lake Townsend near Greensboro, North Carolina, when driver John Peeters broke the world speed record for an electric-powered boat by averaging 114.20 mph (183.8 kmh) on a so-called kilo course, which measures 1 km (0.62 mile) in both directions and was sanctioned by the American Power Boat Association.

The new record obliterated the old mark of 88.61 mph (142.6 kmh) set by Jaguar Vector’s V20E raceboat in 2018. “We came together as a team with a dream. Today, the hard work and ingenuity brought this dream into a reality,” said Peeters, of Arlington, Washington, who holds several hydroplane racing records. “Rarely can one say ‘we are the greatest or best,’ but today we can, [having the] fastest electric boat ever,” he added afterward.

COURTESY PES

The propeller shaft broke during the second run.

On his first run, Peeters posted a single-direction speed of 111.08 mph (178.8 kmh). Without recharging the batteries (a rule in kilo-style events), he recorded an average speed of 117.50 mph (189.1 kmh) in the opposite direction. The average speed of the combined runs was the basis for the new world record. The average speed of the second run is also faster by 1 mph than Vision Marine’s single-point speed record of 116 mph (186.7 kmh) clocked at the 2023 Lake of the Ozarks Shootout. Yet, had things gone as planned, PES might have pushed the envelope a bit further.

“We planned on making three to five runs throughout the day,” said Andrew Robbins, CEO of the Princeton University Electric Speedboat Team and a sophomore who’s studying mechanical and aerospace engineering. “The first run was with a motor tune-up that we knew was comfortable and easy on the boat and an outboard setup that was conservative. The goal for the first run was to make a clean A-to-B pass and take down the Jaguar 88.6-mph kilo record. With a two-way average of 114.20 mph and the return pass being 117.50 mph, the boat was running even better than it had in testing the day before. We were very happy with that result. After the run, we went up in propeller pitch and increased the power slightly, aiming for a low-120 mph two-way average. At the onset of the second run, as the boat was getting on plane, the propeller shaft broke and that was the end of our day.” The prop shaft in question was made from a heat-treated stainless steel, Robbins added but was not sure about the exact composition. He estimated its yield strength was between 100 ksi and 120 ksi (kilopounds per square inch) or approximately 690 MPa to 827 MPa (megapascals).

COURTESY PES

This stern angle shows the modified Flux Marine outboard and Big Bird’s partial plywood construction.

The boat, named Big Bird, is a customized Pro-Outboard hydroplane, built by Ed Karelsen in 1993 and completely refurbished in 2021. The hull structure is a combination of honeycomb-cored fiberglass panels and okoume-plywood panels. The cockpit is entirely fiberglass, while the tunnel and stringers/frame are 3⁄8-thick (10mm) honeycomb and fiberglass panels. The decks and the front sponsons are okoume plywood. Without a driver, the race weight of the boat was 825 lbs (374 kg).

It was powered by a 182-hp (136-kW) electric outboard co-developed with Flux Marine, an electric outboard manufacturer in Bristol, Rhode Island, founded by Ben Sorkin (CEO) and Jon Lord (CTO), both Princeton alumni. They took an interest in the project and became mentors and friends, as over a dozen PES members have interned at Flux Marine over the past three years, and one recent grad joined the company as a powertrain engineer.

Hitting the jackpot on the first attempt creates expectations. If PES is true to its promises to “continue to push the boundaries of what electric propulsion is capable of,” cracking 120 mph is the logical next step. Working toward that milestone, they continue to rely on a network of supporters, including their well-endowed alma mater.

COURTESY PES

Members of the winning team assembled with Big Bird after its record run.

An Interview with the PES Captain

For now, the Princeton Electric Speedboat team holds the world record. But there is no intention to rest on those laurels, as the group has come far in a short time, team captain Andrew Robbins pointed out in this interview.

PBB: Princeton and racing electric boats?

The Princeton University Electric Speedboat Team was started in the fall of 2020 by Nathan Yates, then a junior Mechanical and Aerospace Engineering [MAE] student, and three of his colleagues to race in the Promoting Electric Propulsion [PEP] competition, which is funded by the American Society of Naval Engineers and uses a 1-mile oval on which we run five laps. In the spring of 2021, our 8 [2.44m] runabout did not pass the end of the dock before taking on water. Testing it in the fall of that year revealed the boat was capable of 26 mph [41.8 kmh]. For the 2022 PEP competition, we built a 12 [3.66m] D-stock hydroplane, which was 2.5x faster than anyone else, with a top speed of 42 mph [67.6 kmh]. However, it too did not finish the race as a low-voltage battery failed at the halfway point of the race. For the 2023 PEP competition we brought Big Bird and dominated by finishing the course in 6 minutes and 12 seconds, more than three times faster than the runner-up. Since it is the only race for this series, we are technically national champs for electric circle track racing and hold the world speed record for electric boats, an incredible development for a three-year team.

When and how did the world record idea come about?

In early 2022 Nathan Yates [then team president] and I looked at the D-stock hydroplane and the anticipated speeds it would run and realized it wasn’t too far off the Jaguar Vector V20E electric water-speed record. The initial goal was 100 mph [160.9 kmh]. By February 2022 we had made the decision to go for the record and began to search for suitable hulls and powertrain combinations. I quickly got in touch with JW Myers, who loved the project and helped us tremendously right from the start. He located Big Bird, a 14 [4.3m] Pro-Outboard hydroplane that he has driven many times to set speed records. He also operates Black Sheep Racing [BSR], and their lead driver, John Peeters, came on board immediately as well.

What motivated you beyond “just” setting a record?

Firstly, the ability to push the boundaries of electric technology in the marine industry. The overarching goal of our college circle-track competition is to improve the electric marine technology within the United States. Well, what better way to make advancements than to build the fastest electric boat? Secondly, it was an incredible opportunity to attempt something that hadn’t been done [at the time of the project’s inception]—going 100 mph with an electric boat.

What was your budget, and how was it financed?

As a student team, our budget was much lower than many of our competitors’, so we need to be creative and find the best partners. A portion of our funding comes from the university, mostly from the mechanical engineering and electrical engineering departments, as well as the Andlinger Center and Keller Center. The majority of our funding, in the form of cash and in-kind donations, came from the partners of the team, Flux Marine, Cigarette Racing, Gold Technologies Inc., and the Robbins/Marges Family, to name a few.

Why did you choose a hydroplane?

At the onset of PES, Ben Sorkin pushed us towards hydroplanes for their great efficiency at high speeds and ability to turn hard on a circle track. JW Myers and John [Peeters] of BSR knew that a hydroplane, specifically Big Bird, would allow us to go as fast as possible with the power we had available. BSR recommended the hull, and it was certainly the right choice.

Was Flux Marine the only drivetrain manufacturer considered for the project?

We looked at many different drivetrain and component manufacturers, including building everything in-house. In the end, Flux Marine was best suited to achieve our goals from a technology and mentorship perspective. They were enthusiastic about the project and are now integral to the team.

What can you tell us about the drivetrain?

Peak power during the record runs was 182 hp [136 kW], 6% overdrive gear ratio in the lower unit. The drive (input) gear has 17 teeth, and the driven (output) gear has 16 teeth. It is similar to a 5th or 6th gear in a stick-shift car. This is very atypical and pretty much only found in smaller outboard hydroplane lower units. We used a Bass Racing lower unit, which is popular in outboard racing. We combined the standard Flux Marine closed-loop cooling system with an external water pickup on the underside of the bullet of the lower unit and a liquid-to-liquid heat exchanger in the boat. Props are custom four-blade Dewald Racing Propellers ~8 [203mm] in diameter; trim was nearly neutral with a very slight tuck; prop shaft height was slightly below the bottom of the boat.

Flux Marine offers only 50-kW and 75-kW outboards, so how was this motor modified?

Their engineers helped us to optimize their standard 75-kW [100-hp] outboard for our lightweight racing application. We ran the motor at a much higher rpm than usual, and the peak acceleration power allowed us to extract enough power to achieve the record.

What battery did you use?

This was a ~25-kWh, 400V battery pack from Flux Marine, using lithium-ion cells. With mounting, it weighs 330 lbs [150 kg].

—Dieter Loibner