ShearWater Iii Information, Review, Specs

Sailing Performance & Handling

The Shearwater III is a high-performance racing machine characterized by its "Restricted Development Class" status, which allowed the design to evolve with modern materials while maintaining its classic lines. With a length of 16.5 feet and a beam of 7.5 feet, the boat feels remarkably stable compared to contemporary monohulls but remains highly sensitive to weight distribution. The rig is a fractional sloop with a rotating spar, designed to maximize aerodynamic efficiency.

The technical profile of the Shearwater III is defined by an extraordinary Sail Area to Displacement (SA/Disp) ratio, often exceeding 60. This reflects its "ultralight racer" status, capable of exhilarating speeds on a reach. Handling is governed by twin pivoting centerboards and drop rudders, which allow for precision steering and the ability to sail into very shallow waters. However, sailors must be wary of the "pitch-pole" risk; in heavy downwind conditions, the narrow hulls can bury their bows if the crew does not move their weight sufficiently aft. Historical accounts from early trials noted that the boat was so much faster than its contemporaries that it initially struggled to find a handicap class that could accommodate its performance.

Popular Mentions & Media

The most significant media event in the Shearwater’s history was the 1956 Folkestone to Boulogne race. The sheer dominance of the Prout brothers’ design in this event sparked a global interest in catamarans. The boat also featured prominently in the collection of George O'Day, the prominent American Olympic sailor and builder, who imported the Shearwater III to the United States to promote multihull racing. Its cultural footprint is also visible in early 1950s sailing films, where it was often showcased as the "future of sail."

Known Issues & Buyer’s Checklist

Purchasing a vintage Shearwater III, particularly one of the hot-molded timber versions built by Fairey Marine or Prout, requires a meticulous structural survey.

• Veneer Delamination: In the hot-molded plywood hulls, the "Achilles heel" is moisture ingress between the wood layers. Look for "soft spots" or "pillowing" on the hull surface, which indicate the glue bonds have failed.
• Beam Integrity: The cross-beams (the structures connecting the two hulls) endure significant torque. Inspect the mounting points for stress cracks or wood rot, as these are high-stress areas that can lead to catastrophic hull separation if neglected.
• Centerboard Trunk Leaks: The pivoting centerboard cases are prone to leaking at the pivot pin or along the trunk-to-hull joint. On older wooden models, this area is often the first to succumb to rot.
• Mast Step and Rigging Tension: The Shearwater rig carries a high load for its size. Check the mast step on the main beam for compression damage and ensure the forestay and shroud chainplates are not pulling out of the hull or beam.

Community & Resources

The primary authority for the class is the Shearwater Catamaran Association, which maintains technical archives, racing schedules, and a registry of surviving boats. Because the Shearwater III is a restricted class, the association provides vital guidance on modernizing older hulls with carbon fiber components or updated sail plans while remaining class-legal.

The Verdict

The Shearwater III is a piece of sailing history that still offers blistering performance on the water. It is a boat for the enthusiast who values pedigree and the unique tactile feel of a classic multihull.

Pros:

• Historical Significance: Owning the world’s first production catamaran.
• High Performance: Still capable of outperforming many modern dinghies on a handicap basis.
• Strong Class Support: Active racing community and technical expertise available.

Cons:

• Maintenance Intensive: Older wooden hulls require constant vigilance against rot and UV damage.
• Demanding Handling: Requires an experienced crew to prevent capsizing or pitch-poling in high winds.
• Complex Rigging: The twin-hull setup and rotating spar add complexity to launching and retrieval compared to a simple monohull.