Design and Construction
The Ker 40's hull form is a study in controlled volume. There is more volume forward, particularly around a quarter of the way back from the bow, while aft there are no chines and the hull carries enormous flare without resorting to hollows. That flare pushes the sidedecks around the cockpit wide and gives the boat a broad beam aft, which IRC rewards heavily anchor. The waterline beam, however, is narrower than the Tonnerre and narrower relative to her maximum beam, so the hull moves through the water on a narrow footprint with little drag. The transom carries a lip rather than a rounded corner, and the designer notes this sharp corner yields better hydrodynamic properties.
Construction is infusion with E-glass and epoxy around an SP-provided PVC foam core, M-Core, used throughout the hull, deck, and interior structure. The finish is entirely painted with no gelcoat. Flanged bulkheads remove the need for taping, and keel-head loads are tied into the fore and aft bulkheads and the mast step through two beams of machined aerospace-grade alloy. The designer describes the boat as built like a one-off but productionised, with engineering done in the Ker office in the same manner as a carbon boat using judicious unidirectionals but in glass. A PVC foam core was chosen over Nomex because IRC is believed to penalize Nomex even harder than carbon. Building in carbon at this length would save perhaps 150 kg at most.
Rig and Handling
The rig is a fractional sloop with a Hall Spars NZ mast and boom in high-modulus carbon, twin sets of swept-back carbon spreaders, and rod standing rigging. There are two masthead and one fractional halyard for the kites plus a single jib halyard, and a bolt-on bowsprit carries the downwind inventory. The jib foot can be dropped to deck level, with the sheet leading from a flying ring fairlead on a lateral track at 6:1 purchase, up/down at 24:1, straight to the primary winch. Mainsheet stoppers lead to the winches in a clean deck layout.
On the water the fin has progressed to give a wider groove and make the boat more forgiving to sail. The designer states it has enough weight and stability to go upwind like a train, yet away from the wind it takes off sharply. Testers found her potent upwind despite the light displacement, and she likes to be sailed with twist, keeping the main worked to hold a constant heel angle. In the RORC Myth of Malham, the boat survived 45 knots and averaged 17 to 18 knots downwind for six hours. The source expected sportsboat-like performance, a blast particularly downwind, and Sailing World's judges called her a work of boatbuilding art and excellent under sail anchor.
Accommodations
Below, the Ker 40 is very minimalist. A structural bench seat runs from the saloon back to the transom with pipecots above it. The galley sits to port of the mast and a chart table to starboard, the bare minimum required by the Special Regs, and the heads is plumbed in forward of the main bulkhead. This is a boat whose interior exists to satisfy safety rules, not to host guests.
Known Issues
The boat appeared bang on straight out of the box with no need for major modifications, and the principal owner-facing consideration is the minimalist accommodation and the demands of a lightly built race platform rather than any chronic failure mode.
Refits and Ownership
The production boat represents roughly a 50 percent saving over a one-off custom build, letting owners enter the grand-prix IRC game custom-fast without custom cost. The test boat Catapult was built for an experienced owner primarily for offshore racing and customized with a Harken pedestal, generous nav station, and pipe berths. With a recommended race crew of 11 to 12 and typical crews of 10 to 12, ownership is framed around campaign readiness rather than casual weekend sailing.
The Verdict
The Ker 40 is a semi-custom production racer that translates one-off engineering into a repeatable, competitive IRC weapon. She is aggressive and wicked-up for her size, yet forgiving enough to sail fast across a wide groove, and her narrow waterline with flared topsides is a clever answer to the handicap rule's beam credit.
Pros
- Narrow waterline and flared hull cut drag while earning IRC beam credit
- One-off-grade engineering in production glass at about half a custom build
- Forgiving, high-performance handling with proven 45-knot survival and 17-18 knot downwind averages
Cons
- Minimalist interior satisfies only Special Regs, not cruising comfort
- Light-displacement race platform demands a 10-12 person race crew and campaign-level upkeep
