Tim and Sue Knox have completed a five-day, 124-mile journey down the River Thames, from Lechlade to Teddington, in a boat powered entirely by sunlight — no generator, no shore power, at any point along the way.

Tim Knox is the co-founder of Torkmar, the Northamptonshire company that built the boat, DB1, and Sue is his wife of nearly 40 years.

The couple made the trip during a summer heatwave and nationwide drought, which brought strict lock restrictions to the upper reaches of the river and threatened to derail the schedule before it began.

"The doubters said we wouldn't be able to make this trip in the five days planned," Tim said. "The pragmatists said it was unlikely that we'd make it in seven days. But the optimists, like me, said let's try."

They made it in five, arriving at Teddington Lock on a high tide, with the battery still holding 70% of its charge.

Along the way, the couple cleared river weed through a hatch built into the hull over the winter, waited out a two-hour lock breakdown at Whitchurch, watched a partial solar eclipse from the water at Shillingford, and were joined for a stretch through Oxford by boating YouTuber David Johns of Cruising the Cut.



Tim also spoke to BBC Radio Oxford about the trip while it was underway.

For Tim, the story of the journey was less about the technology than the river itself.

He said: "This isn't an article about a fabulous new solar electric dayboat and how proud the builder is of this boat.

"It's what struck me about the magnificent River Thames on my recent trip — this is a national treasure. All sorts of people, all sorts of creatures come to this river to be nourished. We share this planet, this river, with all creatures, and we have no right to damage their habitat."

The couple saw kingfishers, herons, kites and swallows along the way, and were joined for the final stretch by Torkmar business partner Iain Sommerville and family.

Throughout, DB1's battery — a 5kWh lithium bank fed by a rooftop solar array — recovered charge each day on sunlight alone, even after the delays at Whitchurch cost the crew more than two hours and drove state of charge down to 60%, its lowest point of the trip.

Tim added: "It has been a big week, so much uncertainty.

"But round the bend we see Teddington Lock, and she is celebrating. It's a high tide and water is actually flowing into the non-tidal Thames. The Thames is saying: have some water, water person, and well done."

DB1 is a 19-foot-6-inch dayboat seating up to six people, built around a fully integrated electric powertrain designed for quiet, zero-emission cruising on inland waterways.

A key part of the story is DB1's solar roof, which Torkmar says is the only one of its kind: it rises to collect solar power while the boat is under way, then lowers at the touch of a remote button to fully close and secure the boat at the end of the day.

There are no canvas covers, poppers or press-studs to fit. Because the boat never needs to be plugged in, Torkmar says DB1 is suited to owners who keep their boat on a swinging mooring — out on the river, away from a marina berth — rather than needing dockside power.