Can a tender be both practical and exhilarating?

Captains, crew, and owners often see jet tenders—or most tenders, whether inboard, outboard, or jet-powered—as enjoyable and useful, yet sometimes unreliable or even risky. A mix of high power, fragile components, hard metal fittings and gasoline has traditionally made tenders high-maintenance and occasionally nerve-wracking.

Williams has developed a dieseljet range that tackles these concerns head-on. We had the opportunity to test the Williams 565, and it delivers on both performance and practicality.

Reliable Diesel Power

Power comes from a 150hp Yanmar 4BY3 diesel, or a 180hp option in the “S” version. These engines have a reputation for bulletproof reliability and are backed by Yanmar’s global service network. Once out of warranty, the 565 is relatively simple to maintain—a huge plus for crews tasked with keeping things running smoothly. And best of all, no onboard gasoline storage is needed.

Crew-Friendly by Design

Williams has clearly considered the crew’s workload. The 565’s inflatable tubes are fully removable, though their rugged build makes replacement unlikely. Boarding poles can be slotted in to help guests embark and disembark safely in a swell, and grab handles are everywhere for stability underway. The central driving position gives excellent visibility and fast access to all sides of the boat—something any skipper can appreciate.

Lifting points for craning are easy to reach, and with no exposed props or fins, there’s nothing to gouge the mothership’s paint—or injure the crew. The fold-down windscreen helps reduce vertical clearance for storage on board.

Serious Performance

If you’re thinking all this practicality makes for a dull ride—think again.

The 565’s Yanmar diesel and Williams’ own waterjet propulsion provide crisp acceleration, strong grip in turns, and impressive torque for pulling skiers or toys. Top speed clocks in around 36 knots, and the boat delivers a solid, fun experience even when pushed. Yes, we did get airborne briefly off our own wake—and yes, it made us smile.

Custom Options and Onboard Presence

The 565 feels right at home aboard larger superyachts, with its low-profile, clever design and solid build. For those looking to match the mothership’s styling, Williams offers custom tube colours, upholstery, dashboard finishes, and sound systems.

As Williams dealers, of course we’re big fans—but we’re not alone. Owners, captains, and journalists alike consistently come back with praise for the 565’s balance of safety, power, and ease of use.

If you’re considering a new dieseljet tender that works hard for the crew and still delivers fun for guests, the Williams 565 is very hard to beat.