Ker sailboats: race-yacht designs from Winchester, built by McConaghy Boats
There is no Ker boatyard. Ker Yacht Design is a yacht design office founded by Jason Ker and based in Winchester, UK; the raceboats that carry the name are built by McConaghy Boats, a separate company. Ker designs, McConaghy builds, and rating rules such as IRC, ORC, and Fast40+ govern the racing those designs are aimed at.
Origins and ownership
In 2010, Ker Design and McConaghy Boats teamed up for the first time to produce the Ker 40, a partnership that, from the outset, proved light 40-foot race boats could compete against heavier cruiser-racer rivals. That September, Jason Ker and McConaghy's Rob Brown jointly presented the new boat to a gathering at Middle Harbour Yacht Club in Sydney; at the time, Ker was based in Valencia, Spain. McConaghy went on to build the Ker 33 as well, another production raceboat from the same design-and-build pairing.
The designers
Jason Ker's own path to the design office started in competitive sailing rather than a drafting table. He represented the UK in sailing at senior level at sixteen and won multiple national titles as a helmsman while at Solent University. His early career was a varied composite-boat apprenticeship: building composite yachts near Sydney, conceptual R&D for fast car ferries in Tasmania, and multihull and trimaran superyacht work in the UK. His first design commission came in 1997, the private race boat Shakermaker, and it launched his career designing performance yachts. The breakthrough followed a few years later: the 55-foot Aera, renamed Bribon for the 2003 Admiral's Cup, won all seven of that regatta's inshore races, establishing Ker Yacht Design internationally, and went on to win the overall trophy of the 2004 Sydney to Hobart race.
Aera's success led directly to Ker's highest-profile commission outside raceboat design: at 33, he was recruited to set up and lead the design team for Team Shosholoza, the first South African America's Cup Challenge. Southampton Solent University, which later honored him, credits the team's speed to what it calls his "ground-breaking approach" using advanced computer simulation techniques. Solent awarded Ker the honorary degree of Doctor of Maritime Studies on 10 July 2018. He is also a member of both the International Technical Committee and the advisory council of the Sailing Yacht Research Council, contributing to the development of ORC rating technology -- a standing role that puts him inside the rule-making process his own designs race under.
Construction through the eras
The Ker 40's hull, deck, and interior are built by infusion, E-glass and epoxy laid around a foam core, finished entirely in paint with no gelcoat, and rated ISO Structural A. The Daily Sail reported that the boat uses flanged bulkheads rather than taped joints -- one of several choices aimed, in the designer's words, at productionizing a boat that is otherwise "built like a one-off." Ker Yacht Design markets it as a "production IRC raceboat" that "showed the way with light weight success" -- the firm's own framing rather than an independent assessment, though Sailing World separately called the boat "incredibly well built."
The Ker 33, also built by McConaghy, is constructed from E-glass and core-cell vinylester resin, to ISO 12215 Category A.
Lines and generations
The Ker 40 and Ker 46 were, in time, further developed into the (Fast)40+ and 46+ designs -- a lineage, not an equivalence. The Ker 40+ is a genuinely new boat: its hull form "bears little relation" to the original Ker 40, running much lighter in displacement with deeper draft, less power, and less drag, and it's built in either prepreg carbon or E-glass, with a keel fin optimized both structurally and hydrodynamically behind a composite fairing over a structural casting. It's configurable for Fast40+, IRC, and ORCi rules, and with larger upwind sails can also fit the HPR box.
The design signature underneath both generations is hull volume carried forward, above the waterline -- a trait Ker's office says marks most of its designs, including the 2013 Rolex Sydney Hobart Division winner Varuna, built to let the yacht be pushed hard downwind in heavy conditions. On the original Ker 40, The Daily Sail described that same forward volume concentrated about a quarter of the way back from the bow, paired with no chines aft and, in the designer's words, "enormous flair" without resorting to hollows -- a combination that widens the sidedecks around the cockpit.
The results have followed the rule-optimized brief: a Ker 40 has taken 1st in Class at the Rolex Fastnet Race (2013), 1st Overall at the RORC Myth of Malham Race (2013), 1st in Class at the RORC Caribbean 600 (2014), 1st in IRC 3 at the Middle Sea Race (2025), and 1st Overall at the Loro Piana Giraglia Race (2025), on top of Ker designs' wider IRC record at the China Cup, Rolex Commodores Cup, Cowes Week, and the Fast40 Class.
Who Ker is for
A Ker is a rule-optimized raceboat for an owner chasing IRC, ORC, or Fast40+ results, not a cruising brand with a boatbuilder's name on the transom. Buyers should expect a design pedigree that runs back through Jason Ker's own competitive sailing career, and a construction standard set by McConaghy, a builder capable of infusion-molded, production raceboats built to ISO structural ratings. They should also know, generation to generation, exactly which Ker design they're looking at, since the office's own naming convention -- 40 to 40+, 46 to 46+ -- marks real, not cosmetic, changes underneath.
