Design and Construction
The Alc 40's hull is solid fiberglass, and she was offered with different keel alternatives, one of which is a fin keel cast in lead lead keel option. Lead carries a real advantage over iron here: at 44% greater density it lets the builder use a smaller foil, which cuts wetted resistance and frees a little speed smaller keel from lead density. The hull's length-to-beam ratio is 3.38, and against her peer group she is slimmer than 58% of all other designs, a figure that explains much of her offshore character. Her displacement-length ratio lands at roughly 250, a band that places her among light cruisers and offshore racers. The wetted surface of the bottom is about 365 square feet, a moderate footprint for a boat of this length.
Rig and Handling
She carries a masthead sloop rig. The reference sail plan gives a sail-area-to-displacement ratio of 15.4, which rises to 18.7 with a 135% genoa — enough canvas that she is lively in a breeze yet not overcanvased for short-handed cruising. Sheet sizing is thoroughly documented: jib and genoa sheets run 39.5 feet at 9/16 inch, the mainsheet is 98.8 feet at the same diameter, and the spinnaker sheet is 87 feet at 9/16 inch. The capsize screening value is 1.88, a number that by that formula alone would qualify her to enter ocean races. Her Motion Comfort Ratio is 27.1, more comfortable than 38% of similar sailboat designs, while 54% of comparable designs are heavier than she is.
Performance Envelope
The theoretical hull speed for a displacement boat of this length is 7.4 knots, and the calculated maximum speed is about 6.3 knots. She immerses about 1,227 pounds per inch, so loading her for a cruise noticeably changes trim and draft. With the shallow fin keel she draws just 4.59–4.89 feet dependent on load and can slip into even shallow marinas; the deeper fin option draws 5.74–6.04 feet and still enters most marinas. Those two drafts let a buyer match the boat to his cruising ground.
Accommodations and Power
The boat is a large sailboat but the interior is not itemized. Propulsion is flexible: she may be equipped with an inboard Westerbeke 4-107 diesel rated at 37 horsepower. The Vire make is the engine supplier, and diesel fuel is the stated type.
Known Issues
The single ownership-relevant caution is indirect: the immersion rate of about 1,227 pounds per inch means a heavily loaded Alc 40 will sit deeper and change her documented draft ranges, so a surveyor should confirm actual freeboard against the designed lines rather than trust a spec-sheet draft.
The Verdict
The Alc 40 is a thoughtfully engineered narrow sloop that punches above 1
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ally engineered narrow sloop that punches above her comfort percentile in speed and offshore credibility. The lead fin keel, documented sheet specs, and two-draft strategy make her a versatile used-racer-cruiser, though the thin accommodation record means a buyer must verify livability in person.
Pros
- Lead fin keel option reduces wetted resistance versus iron
- Capsize screening of 1.88 meets ocean-race formula threshold
- Two draft ranges (4.59–4.89 ft and 5.74–6.04 ft) suit varied cruising
- Masthead rig with 135% genoa lifts SA/D to 18.7
Cons
- Motion Comfort Ratio better than only 38% of peers
- Immersion rate of 1,227 lb/in means load sharply alters draft
- No interior or tankage details provided in available material
