Design and Construction
Sparkman & Stephens drew the 12.70 as one of the best Sparkman & Stephens projects of its period, and the result is a fin-keeled masthead sloop of disciplined proportions. Alpa built her with great care at their own construction site, producing only 15 examples in total. The hull is solid fiberglass with a solid fiberglass deck, carrying 9,700 pounds of lead ballast in a 52 percent ballast-displacement ratio that gives her a capsize screening number of 1.72. At 41.5 feet overall with an 11.42-foot beam and a 6.82-foot draft, she is a substantial 18,637-pound cruiser-racer with a comfort ratio of 33.66.
A distinctive feature of the class is the deckhouse configuration. The 12.70 was offered in long deckhouse or short deckhouse versions, but only four short deckhouse examples were built. Those four are regarded as a small masterpiece in their own right, a recognition of how rare and finely resolved the shorter trunk configuration truly is.
Rig and Handling
The 12.70 was a winner at the time in offshore racing, a credential that speaks to both her sail plan and her hull behavior under load rather than to any comfort concession. Her masthead sloop rig carries 788 square feet of sail area against a displacement that yields a sail-area-to-displacement ratio of 17.93—modest by modern light-air standards but well matched to the 7.33-knot hull speed her 29.92-foot waterline suggests. The skeg-hung rudder and fin keel place her firmly in the performance cruiser lineage that Sparkman & Stephens refined through the late 1960s.
Accommodations
The boat is described in two deckhouse layouts rather than in cabin detail, and the principal dimensions tell the accommodation story in broad strokes: a 41.5-foot hull with a 3.48-meter (11.42-foot) beam and 100 gallons of water capacity implies a volume of cruising accommodation that the long deckhouse version would have exploited most fully. The short deckhouse examples, being only four in number, represent the more driver-oriented end of the same platform.
Known Issues
No structural defects, osmotic problems, rigging failures, or systemic construction faults are associated with the class.
The Verdict
The Alpa 12.70 is a rare, carefully built Sparkman & Stephens design that earned her racing credentials without sacrificing the cruising volume her size implies. With only 15 built and four of those in the coveted short deckhouse form, she is a collector-grade expression of late-1960s Italian GRP craftsmanship.
Pros
- One of the best Sparkman & Stephens designs of its period
- Built by Alpa with notable care; only 15 examples produced
- Proven offshore racing winner in her era
- Rare short deckhouse version (four built) considered a small masterpiece
Cons
- Very limited production limits spares commonality and class support
- Modest sail-area-to-displacement ratio by modern light-air standards
