Pure Watercraft, an Electric Start-up

Pure Watercraft's outboard on a bass boatCourtesy Pure Watercraft/Gabe Johnson

Their aluminum bass boat propelled by a low-profile 25-kW electric outboard motor developed and manufactured by Pure Watercraft, two anglers set out to hunt for fish on Lake Washington near Seattle.

Pushed by a conspicuously low-profile motor, we zoomed along the western shore of Lake Washington in a cold northerly under a pale October sun. Our 168 (5.10m) production aluminum bass boat traveled on electricity, so no fumes or engine noise. But quiet it was not, courtesy of the apparent wind that roared around our ears as helmsman Derek Glasscock adjusted the throttle to keep us on a plane while also conserving energy to chase some trout later in the day.

Aboard with us was Glasscock’s colleague Rick Broomell. Both are commercial divers, hold USCG captain’s licenses, and work as field technicians for Pure Watercraft, testing products and training beta customers—most are crew coaches or competitive anglers—in the best use of the electric outboard system the Seattle firm was about to roll out to the public. The compact 25-kW unit was bolted to the stern of our test ride, and despite the beta-character of this prototype, nothing looked out of place or improvised. The setup was tidy, with clean cable runs and an invisible battery pack tucked into the stern compartment, where normally a gas tank resides.

From Tech Ventures to Manufacturing

Pure Watercraft set up shop in 2011 on Lake Union, across from downtown Seattle, in Northlake, adjacent to the Gasworks Park Marina. Now with 28 employees, the business has been funded by seasoned private and institutional investors, some of whom are connected to big Silicon Valley firms and to local tech giants like Microsoft and Amazon.

Approaching their shop, one has to cross the Burke-Gilman bike trail, where throngs of commuters head downtown, many on zippy e-bikes that are popular around the world. Those bikes are a seemingly perfect application for electric propulsion: lightweight, efficient vehicles with limited payload and a battery capacity to cover the desired daily range at greater speed with less effort. And all this for a price that is well within reach for millions of consumers.

Andy Reble, CEO Pure WatercraftDieter Loibner | Professional BoatBuilder Magazine

Pure Watercraft’s CEO, investor and tech entrepreneur Andy Rebele, poses in front of a still-empty aluminum shell with a compact electric motor that fits into the lower unit in line with the propeller.

To mimic this model with boats is the mission of Pure Watercraft and its founder, Andy Rebele, a tech executive, entrepreneur, and investor (i.e., Webvan, CityAuction, Ticketmaster) with a degree in mathematical and computational science from Stanford and an MBA in financial engineering from MIT. Watching and learning from Torqeedo, the German firm that blazed a fresh path for modern electric propul­sion in the recreational boating market since 2005 (see “A Tale of Two Com­panies,” PBB No. 180), Rebele explains why he entered this game: “To build the technology that enables a new era in boating that is more enjoyable, accessible, and environmentally friendly than ever before.”

As I talked to him last fall, prior to the public rollout of the Pure Outboard at the Seattle boat show and the onset of the coronavirus pandemic, it was clear that Rebele’s boating experience, which includes competitive high school and collegiate rowing, influenced his company’s trajectory. Also, he was brought up in San Diego County, California, where he fished for bass and blue gill along the shores and on the waters of Lower Otay Lake near the Mexican border, and, according to the company blog, struggled “with a rented outboard that wouldn’t start.”

Pure Watercraft’s Cobalt Lesson

Listening to Rebele, I got a lesson in economics, strategic decision-making, and market analysis. Yet the path he took was anything but straight or free of obstacles and hiccups. “It’s been eight years. There was a lot of time for mistakes,” he said. “When I told someone that I spent 40%…on mistakes, the reply was, ‘Oh my god, you got away easy.’”

In the early days of development, Rebele bought a used Cobalt runabout on Craigslist to replace its aging V8 inboard with a custom electric-propulsion system. “Coming from the software and Internet industry, I was focused primarily on speed, so we worked with some outside contractors to get something prototyped as fast as possible,” he wrote on the company blog. “We ended up with a boat that performed like a champ (48 mph top speed) but had some downsides. Along the way, we learned a ton about batteries, motors, motor controllers, and all the other tech that has to go into an electric boat.”

pure Watercraft fishing tournamentCourtesy Pure Watercraft/Gabe Johnson

The motor offers anglers access to shallow water in the reeds near the shoreline in addition to silent operation without emissions.

Perhaps the most important lesson was about money. To get the boat he wanted, the modifications and changes would push the price tag above $200,000, way more than twice the original price of a new Cobalt, without solving the range limitations that are still endemic to electric boats. Besides, in the wake of the 2008 financial crisis, the market had changed profoundly for boats in this price class—fewer people were willing to spend a premium on the privilege of going electric. It was a painful lesson but better to learn while still fiddling with a prototype than when production is in full swing. “Forged in the fire of failure” is the alliteration Rebele used to describe his experience of early development.

Making Their Own Motor

He and his advisors looked at other ideas, including the development of an electric outboard, which ran counter to his initial assumption about unit cost and margins. But the Cobalt experience proved that making the drivetrain was a smarter option. It would take more time and money to develop, but it would allow the company to accumulate valuable intellectual property and be freed of the constraints of being tied to one specific boat platform. It also created flexibility to focus on promising niches. “Our idea is to do the deep engineering, make a product that can be high volume, safe, and low cost, tackle the difficult stuff ourselves,” Rebele noted. “In the future we can expand from there, but in the middle of the [global outboard sales] bell curve, there’s a big market.”

ICOMIA Recreational Boating Statistics 2018ICOMIA

Citing this graphic from the ICOMIA Recreational Boating Industry Statistics, Rebele explained the company’s rationale of prioritizing a 25-kW system

Citing data from the ICOMIA (International Council of Marine Industry Associations) Recreational Boating Industry Statistics, he explained why Pure Watercraft started with that particular size motor. They show the North American market’s outsized appetite for outboards above 200 hp (150 kW) and for motors between 27 hp and 100 hp (20 kW and 75 kW), with most of the profit generated by the biggest motors. “We didn’t see anybody who was doing it [right],” Rebele said about zeroing in on the 25-kW niche.

He and his colleagues consider Tor­qeedo a high-quality company, “but they’d approached this problem differently. We are addressing a different power range than they had ever addressed. With the Deep Blue [outboards] they went up top with the motor, which released them from diameter constraints. The only [low-voltage] motors of the under­water type they had at the time were 4 kW and below. Since we were aiming at 20+ kW, we had a much different problem to solve.”

Pure Watercraft’s solution was putting the motor and the two-stage gear set (7.67:1 reduction rate) under­water and in line with the propeller, which means both are passively cooled, eliminating the cost and complexities of another cooling circuit and spiral bevel gears that would be necessary for outboards of conventional design, with the motor above water. Cooling systems and gears are critical components, prone to wear and maintenance needs and thus can make or break a motor’s performance and longevity.

With help from a proprietary outside source, Pure Watercraft figured out how to build its own motor, shaving off nearly half the weight and two-thirds the cost of commercially available products of similar power while also reducing the motor diameter by more than 30%, which is essential for in-line design. The permanent magnet alternating current (PMAC) motor with 25 kW of continuous power weighs about 14 lbs (6.35 kg), or about 13% of the 105-lb (47.63-kg) full assembly. “There are motors that have surpassed that, [but] if we lower that by 5 lbs [2.27 kg], we are only affecting the outboard’s weight by 5%,” Rebele said. On our test run, the outboard reached peak power at 1,500 rpm with a custom aluminum prop with 16″ (40.64cm) diameter and 17.5″ (44.45cm) pitch. It’s one of several types that buyers can choose from, depending on their boat.

Pure OutboardCourtesy Pure Watercraft/Gabe Johnson

The clean, simple profile of the compact Pure Watercraft motor is due in large part to the slim design of the permanent-magnetic brushless AC motor, which needs no separate cooling system.

Pitching to Crew Programs

Picking the right markets took time. The numbers pointed toward tackling social boating on bodies of fresh water first, which means millions of potential buyers in North America who use pontoon boats and small fishing craft on lakes and rivers. Then there are thousands of rowing programs employing motorized coach boats for on-the-water practices and competitions. All of them currently use small two- or four-stroke outboards that might have less upfront cost but are expensive to operate and maintain, while also compromising coaches’ and athletes’ health and the environment with noise and toxic emissions. Rebele’s research indicated these programs pay between $5,000 and $7,000 for a new gas outboard, about $1,000 per year on fuel, and between $500 and $1,000 on upkeep and maintenance for each motor.

Over the long haul, an electric Pure Outboard with one battery for $14,500 (charger not included) is the better deal, Rebele insists, because a full battery charge costs a couple of bucks at most, and there are no oil changes or decommissioning/recommissioning costs. “The University of Washington applied for a sustainability grant to pay for a motor,” he reported. “They had to do a full economic analysis to get the grant, which they won. The analysis showed the payback period was two years for them to buy our [motor] and replace gasoline.” In the course of the expected service life, which is different for battery packs and motors but substantially longer than for gas outboards, Rebele suggested savings of 50%.

UW Eights with coach boatDieter Loibner | Professional BoatBuilder Magazine

Two eight-person shells from the famous crew program at the University of Washington return from practice. The coaches’ launches are powered by conventional fourstroke outboards, but with grant money, the school bought one of Pure Watercraft’s electric motors.

He also detailed environmental benefits when he wrote about the Marin Rowing Association’s plans to convert their coach boats to electric propulsion. In a blog post titled “A Thousand Cars Off the Road” he laid out his thinking and included pollution numbers for gas outboards that still blow all their exhaust into the atmosphere, because they don’t use catalytic converters, which have been mandatory in cars since the 1970s.

Building Batteries

Another important decision resulting from the Cobalt experience was taking on the design and manufacture of a proprietary battery pack, eschewing off-the-shelf solutions. “Beyond 2025, automotive [manufacturers] will dominate the market for battery packs in cars, and you’re not going to be the winner in this, so why get started?” Rebele asked rhetorically. “But to win that war, you have to win the battles between 2019 and 2025. BMW, Tesla, GM—they are not going to sell you a battery at their unit cost. They are going to sell it including a lot of markup for their intellectual property. And if you look at the price people are paying for a Tor­qeedo (BMW i3) battery today, and you compare it to what they asked for battery packs of their own design five years ago, they are charging more for a kWh today [while] the price for Li-ion batteries is declining [by about] 7% per year.”

18650 lithium-ion cellDieter Loibner | Professional BoatBuilder Magazine

About 700 of these 18650 lithium-ion cells are assembled in one of Pure Watercraft’s proprietary 8.8-kWh battery packs.

A big bet was what type of cells to put into a custom battery pack. Pure Watercraft chose to stay away from the larger pouch cells and follow Tesla’s example by using 3.7V cylindrical lithium-ion cells with the 18650 form factor, which are offered with either nic­k­­­­el cobalt manganese (NMC) or nickel cobalt alu­minum (NCA) as cathode material. While a Tesla battery consists of more than 7,000 of these cells, Pure Watercraft’s has only 768.

These 18650 (18mm x 65mm) cells are ubiquitous in car, electronics, and hand-tool battery packs. They come from premium suppliers such as LG, Samsung, Panasonic, or Amphenol and might pack less energy than pouch cells but are much easier to manage in case of cell failure. I asked Rebele about variance in cells from different suppliers: “When we made that decision, we didn’t think [the source] mattered,” he replied. “But now we know there are anomalies between cells from different manufacturers that use specialized…processes. You bond the cells slightly differently, depending on which supplier they’re from. The top manufacturers have consistent enough cells [so] that you are of more variance than they are. With lower-quality suppliers, [cells] are the variance, and you are not.”

The standard capacity of a Pure Outboard battery pack is 8.8 kWh at 350V of nominal voltage. The anatomy is similar to that of an electric vehicle battery, except that it is much more compact, with only three circuit boards (one master, two slaves). The pack has a volume of 49.5 l (1.75 cu ft) and measures 575 mm x 375 mm x 225 mm (22.64 x 14.77 x 8.86). It comes with active thermal management, is IP67 water resistant, and can connect to another pack to increase capacity. While Pure Watercraft lists the energy weight and volume at 164.5 Wh/kg and 177.8 Wh/l, respectively, Rebele intimated that these values are due to increase.

One pack retails for $8,500, which means the cost per watt hour is a bit less than $1. At 118 lbs, it can be shipped by FedEx or UPS, an important convenience factor for selling direct. Larger batteries would have to be delivered by truck and stored at a distribution warehouse, which drives up cost.

The 6.6-kW battery charger with built-in controller lists for $2,000 and could serve multiple boats.

Pure Watercraft’s Boat Packages

Rebele contends it is an inefficient value chain if the price for a battery pack is marked up from the supplier to the powertrain maker and again to the customer. To him, the notion that boaters are willing to pay almost any price for what they want is somewhat myopic and limited to the luxury segment. He thinks most consumers are price conscious. That explains Pure Watercraft’s decision to partner with Bass ProShop on the Tracker 175 (177/5.36m) aluminum bass boats built by White River, and Highfield’s small RIB Classic 360 (1110) and RIB Classic Deluxe (126) rigid aluminum inflatables, which are popular yacht tenders and suitable for the 25-kW outboard. “The idea is to pick the best partner in each of the biggest boat segments,” Rebele said. “The customer should be able to count on anything we sell being high quality, thoughtfully put together, and attractively priced.”

Tracker 170 bass boatDieter Loibner | Professional BoatBuilder Magazine

Pure Watercraft packages small boats with the electric motor and one or two batteries. At press time, the Tracker Pro aluminum bass boats (top) had yet to be announced.

Boat packages for single-battery systems range from $24,000 to $29,000, which is roughly twice what similar boats would cost with a 40-hp four-stroke outboard, but it’s not $200K or more for the privilege of going electric. The performance numbers for the RIBs published on the company website promise a top speed of 25 mph (21.8 knots) with a range of 11 statute miles (17.7 km), which increases to 100 miles (161 km) when limiting speed to 5 mph (4.3 knots). Range at wide-open throttle increases to 22 miles with two batteries.

To keep control of the process and to educate customers about using their boats with a new propulsion system, Pure Watercraft sells directly to consumers. “A typical dealer will not do that, because the margin they make per unit isn’t worth the effort,” Rebele explained. “It gets easier later, so we may consider working with dealers/distributors in the future.”

All boats in the company’s packages were designed for combustion power; so, does Rebele consider partnerships to design and/or build custom boats optimized for electric propulsion? Offering more efficient hullforms and less weight could help address consumer’s range anxiety, which is what Zin Boats on the other side of Lake Union is doing (see “Piotr Zin’s New Electric Speedster,” PBB No. 184). “Eventually that’s what makes sense,” he answered. “The ideal hull would be built from the outset for our propulsion system, but in the short term, the customer gets a better value from a hull that’s made [cost-]efficiently at [high] volume, rather than one that’s more efficiently designed but inefficiently produced at low volume.”

Courtesy Pure Watercraft/Gabe Johnson

The first official package boat by Pure Watercraft are two small rigid inflatable boats by Highfield. They were introduced at the Seattle Boat Show 2020.

Tech Culture

In Pure Watercraft’s office, the company’s similarity to a tech start-up during the dot-com days in the 1990s is quite obvious. Back then, knowing and caring nothing about social distancing, they worked cheek to jowl hunched over laptops on a mission to change the world while sharing a desk, a phone, or a pizza. In a similar spirit, Pure Watercraft’s digs are a bit more refined. No need to meet at a corner coffee shop; there’s a conference room for that. A soundproof cabin provides privacy for calls. A healthy, delicious buffet-style lunch in the galley area is on the house, just like at large tech firms, where several of Pure Watercraft’s crew came from.

Pure Watercraft lunch buffetDieter Loibner | Professional BoatBuilder Magazine

Digital marketing manager Gabe Johnson and product manager Annie Zamojski fixing lunch at the buffet.

“I’m not a boater, but I love being on water and I have friends with boats,” said product manager Annie Zamojski, who’s responsible for partnerships with boatbuilders. Before joining the firm, she worked for Amazon in London, England, so this move was quite a change. “Thinking about what happens in other transportation industries, [electric power] made sense to me, even with range anxiety still being a hurdle,” she explained. “We are lucky to follow [trends set by] Tesla and e-bikes.” In her late 20s, Zamojski is part of the Millennial generation, which is accustomed to sharing big-ticket items such as cars and boats. She’s collecting feedback from the market to fine-tune her marketing efforts, including traditional channels like exhibiting at trade shows but also pitching to boat clubs and sharing outfits.

Pure Watercraft recruiter TJ EwingDieter Loibner | Professional BoatBuilder Magazine

TJ Ewing, the firm’s chief recruiter and a naval architect.

The two-dozen employees possess a range of talents and impressive extracurricular abilities. Bringing them on board is the job of TJ Ewing, whose official title is Head of Talent. Prior to joining Pure Watercraft through a mutual acquaintance of Rebele’s, he’d worked in Hungary, where he ran a tech center for LogMeIn and helped with the acquisition of GoToMeeting. His relevant talents include a degree in naval architecture from the University of Michigan and work as a forensic engineer for the Norwegian shipping company Stolt-Nielsen. “I like the idea of electrifying the marine industry and filling up our production and the go-to-market team,” he explained. He’s recruiting from places like Stanford and UW, helped by the rowing past of several staff members. The fact that a former Tesla engineer and product designer joined the staff adds to Pure Watercraft’s cachet. “The challenge is always finding the right talent at the right time,” Ewing said.

The Pure Watercraft Workshop

The company’s shop is about a minute’s walk down the hill from the office. Along the way, an electronically secured gate keeps unregistered visitors in check, limiting access to the workspace that’s adjacent to the docks of Gasworks Park Marina. This place is neat and organized. Stockroom shelves are stacked with blue-labeled bins holding fuses, motors, wires, and the housings for the battery packs with angled connectors that minimize installation space.

Off-limits was the area where the engineers applied robotic technology and ultrasonic welding to assemble the batteries from 18650 cells. While it’s adequately sized for now, it would need to expand considerably or move to a different facility when production ramps up.


Pure Watercraft Hickman Sea SledDieter Loibner | Professional BoatBuilder Magazine

As suggested by the battery in the cockpit, this well-preserved original Hickman Sea Sled, bought online from a collector, was converted for use on test rides.

On display were collectibles topically related to the business and sourced online via eBay or Craigslist. A 1930s-vintage Minn Kota Troller 6–12V electric outboard with a curved shaft and two-blade prop looked like a Jurassic insect compared to the sleek Pure Watercraft model. Clamped to the same rack was an ancient Seahorse gas outboard, resembling a shiny instrument of torture. And an original Hickman Sea Sled (see “Take 5 for Jim Kyle,” PBB No. 182) sat on a trailer next to a pontoon boat. On Craigslist, Rebele found this restored artifact complete with forward cockpit, wooden slats for floorboards, and a brass bilge pump in the motorwell. The Pure Watercraft battery hinted that the boat also serves as a test platform.

In the shop I also ran into Broomell and Glasscock, my two shipmates from the test ride, who were ensuring that the boats were in trim, with charged batteries and updated software. They were troubleshooting a throttle problem that had limited the bass boat to displacement speed during another spin. “It was related to the data reader,” Glasscock said. “An easy fix.” Spotting an empty aluminum motor case waiting to receive a motor and controller, I asked about installation. “This is still a beta version, [but] total assembly takes less than a man-day.” He did not say if this too might get done with robotic assistance in the future.

  • Pure Watercraft electric motor
    At the heart of the 25-KW outboard is this slender electric motor that fits into the lower unit and obviates the need for a separate cooling system as it is needed for motors that are out of the water.

Pure Watercraft’s Crisis Management

While Pure Watercraft continues to exhibit typical qualities of a tech start-up, the firm is also more mature, having learned hard lessons and adjusted course accordingly. Yet it also remains closely connected to production builders, because every one of its motors needs a boat to push. Back in the fall of 2019 the challenges on the horizon were straightforward: securing funds to go to market, anticipating uncertainties of the world economy, and wrestling with what Tesla’s CEO Elon Musk famously called “production hell,” i.e., managing schedules, balancing supply and demand, and scanning for the best deals on everything from battery cells to boats.

Then a virus got loose, and the sky came crashing down.

Just when the news of shutdowns and layoffs by large production builders including White River, Brunswick, and Groupe Bénéteau reached a crescendo, my phone rang. It was Rebele and he was in a splendid mood. “When others retreat, we attack,” he replied when I asked how he was getting on. That’s a page from Warren Buffett’s play­book, but Rebele had reasons to be optimistic: A big funding round was expected to close on favorable terms as this issue went to press, and the government’s stimulus package included useful backstops for small businesses, obviating the need for him to lay off or furlough anyone. “We just hired a production manager,” he said, noting that the talent pool was deeper and wider with all the layoffs in manufacturing. Furthermore, in the works was an acquisition of assets from a builder that was about to close. And lastly, a recent trip to Washington, D.C., opened some (painstakingly sterilized) doors to government business, a boon in times of crisis when consumer demand is in the gutter.

“For a long time, we did things with more enthusiasm than money, so we learned to operate on a shoestring budget,” Rebele said. Now, resilience gained through “the fire of failure” serves Pure Watercraft well as it navigates some tricky but promising waters looking for all the hard, smart work to pay off.

Dieter Loibner is the editor at large of Professional BoatBuilder.