Williams DieselJet 415

Williams Jet Tenders is a British manufacturer founded in 2004 by Roy Parker and brothers Mathew and John Hornsby, building out of an 80,000 sq ft purpose-built facility in Oxfordshire, England. The company traces its roots to a converted garden shed in rural Oxfordshire where the Hornsby brothers began handcrafting boats in the mid-1990s; the formal company registration followed in September 2004.

Williams is the build we ask for when an owner's programme demands a jet-propelled tender that earns its keep across the full yachting day - short transfers, watersports, and heavy guest loads alike. Their proposition is volume: six ranges, seventeen-plus models, covering yachts from 38ft to 40m and above. The entry-level TurboJet and SportJet lines use BRP Rotax petrol engines and jet drive propulsion with no exposed propeller, carrying up to seven passengers at speeds into the upper-forties of knots. The DieselJet range steps up to Yanmar inboard diesels and seating for six to twelve, suited to larger platforms. For programmes running a 40m-plus mothership, the EvoJet 70 is the build to specify: a 7.0m waterjet-powered craft with inboard diesel, seating for thirteen, and multiple boarding locations. SOLAS-compliant variants of the 505, 565, and 625 cover mandatory life-safety requirements for yachts over 500GT without abandoning the standard Williams fit and finish.

Every hull is hand-built by a dedicated team and undergoes an on-water test procedure before dispatch. Williams holds strong factory-fitment relationships with Princess, Sunseeker, Fairline, Azimut Benetti, Ferretti, and Sanlorenzo, with many production models dimensioned specifically around a Williams garage. We'd put the brand alongside the best-supported tender choices in the market at this price tier.