Solar-Powered FluxJet Kayak: 22 Miles on Solar Alone | Part 2 of 3

In Part 1, Jason Woods converted a stock FluxJet into a solar-powered kayak in 24 hours, using parts already in the shop. Part 2 is where the build stops being a workshop experiment and has to survive a real river.

The plan: launch on the American River below Nimbus Dam, run the full length of the river to the Sacramento River confluence before dark, and do it on solar alone. No plugging in, no swapping batteries, just whatever the panels could harvest along the way. The only deadline that mattered was sunset, because the night leg comes next.

He made it. The Garmin at the confluence read 22.2 miles in 7 hours and 42 minutes, and the battery showed 41 volts, still fully charged. This is how the day went.

Launch Morning: A Heavy Boat and a Dropped Battery

The day did not start smoothly. The boat was loaded right up to its weight limit: camera gear, cables, power systems, a second battery, and warm overnight gear in a dry bag for the night leg still to come. Then the crew dropped the battery that morning, hard enough to push a cable out of the charge controller. Luckily the system still worked, but it was not the start anyone wanted.

Jason's own summary at the launch: do not try this at home. First job was simply finding out whether the kayak would float with everything in it. It did, riding better than he expected, and the run was on.

First Miles: Making More Power Than He Used

Within minutes of pushing off, the numbers looked promising. The panels were generating 40 to 49 watts in the early light, already more than the jet drive was consuming. At one early check the motor was drawing about 20 watts while the kayak made 2.8 miles per hour, and once he got into the current he was rolling at 4.2 miles per hour with generation climbing past 100 watts.

In Jason's words, the kayak was running 100 percent solar. The math he had to beat was simple: the stretch from Nimbus Dam down to the Sacramento River confluence is roughly 25 river miles by his route estimate, and all of it had to happen in daylight. Navigating the American in the dark, with its rocks and shallows, was not part of the plan.

Skinny Water: Skimming Rocks and the First Drag

The upper American is shallow, and it did not take long to prove it. Inside the first quarter mile, Jason was out of the seat, taking his own 200 pounds off the boat and pushing it through water too thin to run. The technique for the rest of the shallows was the same all day: keep the nose pointed downriver, never get sideways, and skim over the rocks rather than clip one and get whipped around by the current.

This is where a jet drive earns its keep. There is no propeller or fin hanging below the hull, so the kayak can slide through inches of water that would stop a prop-driven boat cold. Even so, there was dragging, scraping, and more than one moment of desperately holding a line through a little channel while the tail tried to swing out.

The San Juan Rapids: The One Class 2 Section

Most of the American on this stretch is class 1 water. The exception is the San Juan Rapids, the one class 2 section, and the obstacle Jason had been thinking about since the launch. His navigation showed the choke point coming, a pinch of rocks in the channel, so he pulled over and scouted it before committing.

The plan: stay as close to the left shore as possible and go through at full speed. With the boat carrying this much weight, the tail swung hard in the current, but he held the line and shot through clean. His verdict, twice in a row: that was a 10 out of 10.

The Solar Balancing Act: Shade Costs 100 Watts

The day's quiet lesson was shade. Jason's own flag, folded down partway into the run, had been throwing a shadow across the panels, and leaning back in the seat shaded them further. The difference was not small: roughly 140 watts unshaded versus about 40 watts shaded. On a run where every watt is range, panel shade is a real cost, and he spent the day managing sun angle the way other boaters manage fuel.

It mattered for a bigger reason than the daytime miles. The goal was to finish the American with the battery fully charged, because whatever power he banked in daylight is what the night leg runs on. At the 10-mile check, 2 hours and 52 minutes in, the picture was almost hard to believe: top speed already 10.8 miles per hour, battery at 40.1 volts, and the system holding net zero while also powering the sonar and the cameras. Full-power bursts in the rapids dipped the voltage briefly, and then the sun simply brought it back.

Rocks, Weeds, and One Cast at a Boil

It is the beginning of the salmon run on the American, with steelhead and big stripers moving up the river, and Jason lives right by the Nimbus hatchery. So when a huge boil erupted within casting distance, the fishing rod came out. The weeds were thick in that stretch, which is its own argument for a jet: no prop to foul, just keep moving.

The scariest moment of the day was quieter. Two big boulders appeared with almost no warning, and the only option was to shoot the gap between them. He clipped the right side, dragged bottom over the shallows around them, and came through upright, very aware that rolling a boat this loaded, in water that thin, would have been a bad afternoon.

His favorite trick of the run is worth stealing. A FluxJet can run a foot off the shoreline in inches of water, where the current is barely moving, even loaded the way this boat was. He rode that soft shoreline water past riffle after riffle instead of fighting the main current, the same line the salmon use coming up.

The Guy West Bridge: 18.3 Miles In

Late in the run, Jason announced he had made it all the way to the Golden Gate Bridge. He had not. It is the Guy West Bridge at Sacramento State, a red suspension bridge built in 1967 as a scaled replica of the Golden Gate, and he happily admitted it was serving as inspiration to keep going.

The check at the bridge: 18.3 miles in 5 hours and 44 minutes, with 48 minutes of stops along the way, including a burrito bowl eaten with a scooper fashioned from its own cardboard packaging, because the fork never made it into the boat. His one real regret from the day is a builder's note: the panels should have sat further back, so he could have used his seat properly instead of perching uncomfortably for eight hours.

The Confluence: 22.2 Miles, Zero Onboard Power Used

With the sun getting low and the first buildings of downtown Sacramento in sight, the river widened, and there it was: the Sacramento River. Jason spun the kayak around for a look at the confluence, then read the Garmin out loud.

What Part 3 Has to Answer

Part 2 ends at the confluence, not at a dock. The battery sat at 100 percent, too full to take another watt of charge, so the only way to capture the last of the day's light was to keep driving. Ahead of him: the big water of the Sacramento, big boats, jet skis, party boats, and fading daylight.

Part 3 picks up exactly there, on the night run. The open questions are the honest ones: how far does he get in the dark, when does the battery finally start to dip, and where does this finally end? If you are new to the boat itself, start with what is included with a stock FluxJet, then watch the run.

Solar River Run FAQs

How far did the solar kayak go in Part 2?

22.2 miles, from below Nimbus Dam down the American River to the Sacramento River confluence, measured on Jason's Garmin. That is the full daytime leg of the run, completed in a single day.

How long did the Part 2 run take?

7 hours and 42 minutes total, with 6 hours and 42 minutes moving and just under an hour stopped. The moving average was 3.3 mph and the top speed was 10.8 mph, hit in the fast water.

Did the battery run down during the run?

No. At the confluence the battery showed 41 volts, fully charged. Jason's summary was that the kayak used zero onboard power for the 22.2 miles, and the solar panels also powered the sonar, the cameras, and his phone along the way.

How much power were the solar panels making?

It varied with sun angle and shade: roughly 40 to 49 watts in the early light, over 100 watts once the day got going, and up to about 140 watts unshaded. Shade from his own flag and seat could drop output to around 40 watts, which is why he managed shadows all day.

What was the hardest part of the run?

The San Juan Rapids, the one class 2 section on the route, in a boat loaded to its weight limit. The shallows were the constant second challenge: dragging through skinny water, skimming rocks, and threading a gap between two boulders with a brief clip on the way through.

Is the solar setup a FluxJet product I can buy?

No. Like Part 1, this is a one-off experiment built from parts in the shop, run to learn what solar can add to the kayak. Part 3 continues the same run into the Sacramento River at night.