On June 24th, in the heart of the New England boating season, Tenderly, a Highfield Sport 660 powered by Flux Marine's 100HP electric outboard, quietly slipped away from her slip in Bristol, Rhode Island, and set course for Block Island—41.9 miles away across open water.

By 2:03 PM, without burning a drop of fuel, she was securely tied up at Payne’s Dock, having completed the voyage in just over four and a half hours.  

This wasn’t a stunt. It wasn’t organized or planned by Flux Marine. It wasn’t done under tow or in flat-calm conditions. It was, as captain and boat owner, Steve described it, “just another day on Tenderly.”  

But in truth, this trip marked a major milestone for the future of electric boating.

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About the Boat  

Tenderly is a Flux-powered Highfield Sport 660—a rugged and versatile 21’ 10” aluminum RIB built for offshore handling. With oversized tubes and a deep-V hull, it delivers both speed and stability in a wide range of conditions. Power comes from a 100HP Flux Marine electric outboard paired with a 112 kWh integrated battery bank. The Flux propulsion system provides the power, acceleration, and torque to jump on plane quickly, carve confidently through chop, and cruise with ease at speed.

The system features:

• Touchscreen user interface with real-time performance data

• Advanced thermal management and energy monitoring  

• Overnight charging via standard shore power and fast charging compatibility  

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The Journey: 41.9 Miles, Zero Emissions  

Captain Steve left Bristol at 9:31 AM with full battery and favorable tide. Conditions varied throughout the trip, including some chop and strong sun, but Tenderly stayed on course and on pace. “I was confident the whole time,” Steve reported after the journey. “It’s not often you finish a 40+ mile crossing and still have 19% left in the tank. That’s range with a buffer—and peace of mind.”

Here are his stats from the trip:

• Distance: 41.9 miles  

• Time: 271 minutes (approx. 4.5 hours)  

• Battery Used: 82.7% of 112 kWh capacity  

• Energy Remaining: 17 kWh upon arrival  

• Average Speed: 9.4 mph

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Having enjoyed a day on Block Island and having charged Tenderly overnight, the next morning Steve and his wife made the trip back home to Bristol in 138 minutes, at an average speed of 18 mph. "It felt pretty amazing to make this trip,” said Steve. “[It] means the continuation of a brilliant technology built in Bristol — that is good for Bristol and good for the planet."

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Validating the Advantages of Electric Boating

Tenderly’s trip was validation of something we believe deeply at Flux Marine: electric marine propulsion is ready for real-world boating. It delivers the power, range, and reliability needed for true on-water adventures, and provides a better boating experience.

With electric propulsion, the quiet replaces engine noise, the smooth ride eliminates harsh vibration, and the low-maintenance design means less time in the shop and more time underway. It’s a cleaner, calmer, and more connected way to boat.

This summer, we’ll keep pushing the boundaries with longer trips, expanded range testing, and more systems in the field. Tenderly is just one of many vessels running our latest technology, and every mile brings new insights.  

If you’re interested in experiencing electric boating for yourself, sign up for a sea trial on a Flux demo boat.

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