Designed by Mike Mills and built in Argentina by King Marine for Summit Yachts, it has racing in its bones but was conceived as a genuine dual-purpose boat that could also take a family cruising. It proved its speed early, winning Block Island Race Week and the New York Yacht Club's Annual Regatta before moving on to the European circuits.
Design and Construction
Mills drew a slim, low-drag hull with deep, CFD-refined foils. The production boat combines a lead-bulb, narrow-chord keel with a high-aspect rudder—a pairing reviewers expected to deliver excellent upwind performance and a well-balanced helm.
The hull and deck are built from vinylester, vacuum-consolidated composite sandwich, with a foam core and a blend of biaxial and unidirectional E-glass. Construction follows the rugged standards of the IRC rule, with scantlings meeting the EU's CE Category A offshore requirement. The hull and deck are joined through a molded toerail in accordance with ORC rules, structural bulkheads are bonded on all sides, and an anodized aluminum frame forms the mast step.
The rudder has a carbon-fiber spade stock, a choice that made one tester uneasy. The molded nonskid is superb, while the deck plan provides working room for a racing crew and comfortable places to sit under cruise.
Rig, Deck Layout, and Handling
The King 40 carries a swept, two-spreader carbon rig. Two sets of swept-back spreaders eliminate the need for running backstays and simplify sail control. Discontinuous rod rigging supports the standard carbon-fiber spar by King Composites, which is paired with an aluminum boom.
The fractional sailplan uses non-overlapping jibs and flies masthead kites, including a masthead A-sail or spinnaker. A custom carbon spinnaker pole or sprit was available.
The deck layout keeps lines tidy: the mainsheet, traveler, and jib sheets all run below deck. Twin alloy wheels on composite pedestals provide clear visibility on either tack. Most of the deck hardware is from Harken, supplemented by a few Spinlock clutches, while the portlights and hatches are Lewmar. Summit also offered an optional hydraulic backstay adjuster.
At 15,655 pounds displacement, the boat has heft and a solid feel in the water.
Accommodations
Below, the King 40 is surprisingly comfortable. It will never be mistaken for a floating condo, but it provides comfortable bunks, a spacious and functional settee, and a serious navigation station.
The saloon has an off-white finish with wood trim. Opposing settees flank an easily removed drop-leaf table, and a forward-facing, sit-down navigation station stands opposite the galley, topped by a clear-coated carbon-fiber counter.
The galley is exceptional. It includes a single stainless-steel sink set into a clear-coated carbon-fiber counter, a two-burner stove outboard, and a large top-opening icebox. Refrigeration was optional.
Sleeping space runs to three double berths. There are two aft cabins, with a single berth to starboard and a double to port, plus a forward stateroom containing a good-sized V-berth, bureau, and hanging locker.
The enclosed head to starboard is an integral composite molding with a shower sump and overhead hatch. Hot and cold pressure water is supplied from two tanks holding a total of 55 gallons.
Engineering and Model Updates
Standard power is a 39-horsepower, three-cylinder Yanmar 3JH4 X SD50 diesel connected to a sail drive with a folding propeller. The electrical system includes two Group 31 batteries, and the 31-gallon fuel tank has an inspection plate.
In 2010, Summit offered the former King 40 with new features that included cutaway sidedecks aft, refining the cockpit ergonomics for both racing and cruising. Designer fabrics were also available for the settees, allowing owners to tailor the saloon.
Verdict
The King 40 is a thoroughly modern, dual-purpose 40-footer: a Mills-designed, IRC-bred racer with a proper interior and offshore-grade construction. It suits crews looking for speed as well as families that want to cruise, although the carbon-fiber rudder stock and racing-derived ergonomics are worth weighing.
Pros
- Slim, low-drag hull with a CFD-refined lead-bulb keel and high-aspect rudder, designed to provide a balanced upwind helm
- Vacuum-consolidated sandwich construction meeting the CE Category A offshore standard
- Clean deck layout with below-deck sheet leads, twin wheels, and a swept carbon rig that needs no runners
- Genuine cruising interior with three double berths, an exceptional galley, and a serious navigation station
Cons
- The carbon-fiber rudder stock drew reservations from one tester
- The accommodation plan is functional rather than condo-spacious
- The deep, narrow-chord keel limits access to some shallow cruising grounds
