McConaghy MC55 Sailboat Review, Specs, and Listings

Approximate drawing

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The McConaghy MC55 stands as the smallest catamaran to wear the McConaghy badge, and it carries a design identity entirely its own rather than a scaleddown echo of larger sisters. Conceived by Ker Yacht Design and built by McConaghy Boats, the boat is a 15.87metre hulllength multihull (a 17.94 m LOA per one builder specification, or 18.90 m in another) that threads a deliberate line between cruising comfort and carbonframed performance. Its presence is immediate: a full carbon hull and deck finished in highgloss twopack polyurethane, built around vacuuminfused Carbon and Corecell panels for lightweight strength and rigidity.

Measurements

Dimensions 01

Length Overall
Length on deck
Waterline Length
Beam
Draft
Maximum Headroom
Air Draft

Construction & hull 02

Construction
Hull Type
Keel Type
Ballast
Displacement
Water Capacity
Fuel Capacity

Rig & sails 03

Rigging Type
Mainsail luff
Mainsail foot
Foretriangle height
Foretriangle base
Forestay Length (estimated)
Sail Area

Calculations 04

Sail Area to Displacement Ratio
Ballast to Displacement Ratio
Displacement to Length Ratio
Comfort Ratio
Capsize Screening Ratio
Hull Speed

Design and Construction

What separates the MC55 from more conventional cruising cats is the thoroughness of its carbon approach. The hull, deck and structure are vacuum infused using Carbon and Corecell panels, and the boat is meticulously crafted for the most part in carbon. The inverted bows feature a chine in the stem that continues aft in pronounced fashion just above the waterline, while a step in the deck edge is echoed in the design of the hull windows — a coherent styling language rather than applied decoration. Below the waterline, two articulating composite centreboards are hydraulically deployed with three preset positions, adjustable from 1.3 m retracted to 3.7 m fully deployed, giving the platform a draft range quoted between 1.3–3.7 m by the builder and 1.35–3.75 m by the reference survey. At a lightship displacement of 15 tons across an 8.24–8.9 m beam, the structure's rigidity is a function of the controlled vacuum infusion rather than added mass.

Rig and Handling

The MC55's sail plan is built around a carbon fibre mast and V-boom carrying 150 m² of upwind sail area, with a square top mainsail and self-tacking furling jib in North Sails 3Di OCEAN 700. Two Yanmar 57 hp engines with sail drive and feathering propellers provide auxiliary power, paired to a single electronic throttle control mounted to the starboard helm and an engine instrument panel at the helm position. On deck, a control station on the flybridge is designed to give the boat a cruising rather than a racing feel, and the large steering wheel can be moved so the helmsman can position themselves to windward or to leeward — a concession to sightlines and comfort rather than regatta trim. Internally, twin helm stations let the crew command from weather-protected positions, while twin forward helm stations keep the crew connected to the bow.

Accommodations

The MC55 is offered in two accommodation layouts: a four-cabin arrangement with all cabins en suite, or a three-cabin version that opens space for a larger master suite. In the three-cabin guise the starboard hull is dedicated to the owner's stateroom with a private lounge, dressing room and ensuite, while the port hull carries two additional guest cabins with their own bathroom. Social life centres on a wide saloon with large windows running the full length of the hulls and fully retractable glass doors aft; inside, a retractable aft window complements the large bay window to open the saloon completely to the outside. The galley is arranged open-plan to the saloon and centres on a generous island with Corian-type countertops and twin 160 L Isotherm fridge and freezer drawers, creating an apartment-like feel suited to family living. Honeycomb-core joinery panels, lightweight timber laminate and soft fabric liners carry the refined modern interior tone. Outside, the expansive aft deck holds port and starboard settees, an electric barbecue, wet bar and hydraulic swim platform, while the forward cockpit offers a sheltered second social space.

Equipment and Energy

As standard the MC55 integrates 4.5 kW of solar panels into the coachroof, paired with a 50 kWh battery system and full Victron energy management. Navigation is covered by dual 12-inch touchscreen chartplotters, dome radar, GPS, VHF and a Madintech autopilot fitted as standard. The engine rooms carry insulation, fresh-water cooling, Racor 500 fuel filters, exhaust waterlocks and mufflers, with two fuel tanks of approximately 230 litres each, two fuel level sensors and two deck fillers supporting the 460 L total fuel capacity.

Known Issues

The documented record for the MC55 contains no reported structural defects, flooding paths, or systemic failures. The available specifications describe certified construction and equipment without flagging maintenance liabilities, and no owner-report or survey source in the record raises a safety-relevant concern.

The Verdict

The MC55 is a distinctively styled, thoroughly carbon-built cruising catamaran that uses hydraulic centreboards and a Ker Yacht Design hull to pair shallow-draft access with deep-board windward ability. Its accommodation and energy packages are integrated rather than bolted-on, and the boat reads as a considered cruiser rather than a stripped racer.

Pros

  • Full vacuum-infused carbon and Corecell structure with high-gloss finish
  • Articulating hydraulic centreboards with three preset draft positions
  • Twin internal and forward helm stations for sheltered command
  • 4.5 kW solar with 50 kWh battery and Victron management as standard
  • Three- or four-cabin layouts including a dedicated owner's hull

Cons

  • Sources differ on LOA (17.94 m, 18.90 m, 15.87 m hull length)
  • Flybridge cruising orientation may not suit owners seeking race-derived trim

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