F-9 A Information, Review, Specs

Sailing Performance & Handling

The F-9A is defined by its exceptional power-to-weight ratio and a righting moment of approximately 47,000 foot-pounds, providing a level of stability and speed that far outstrips monohulls of similar length. According to technical specifications maintained by Multihull.nl, the standard rig features a 40-foot fixed mast, though many owners opted for the F-9R (Racing) configuration, which utilizes a 42.5-foot rotating wing mast to further reduce drag and enhance lift.

On the water, the F-9A is described by Good Old Boat as a high-performance platform capable of exceeding 20 knots under the right conditions. Its deep daggerboard allows for impressive windward performance, pointing higher than most cruising multihulls, while the kick-up rudder and shallow draft (approximately 1 foot 4 inches with the board up) permit exploration of thin-water anchorages. Because the boat is an ultralight design, it is highly sensitive to weight; performance degrades noticeably if the vessel is over-provisioned for long-term cruising.

Interior Comfort & Variations

Unlike smaller daysailing trimarans, the F-9A offers a legitimate, albeit compact, interior living space. The "A" in its designation typically refers to the aft-cockpit configuration, which prioritizes a larger main cabin and a V-berth forward. The layout generally includes two long settees in the main saloon that double as berths, a small but functional galley, and a head area that can be curtained off for privacy.

Farrier also developed the F-9AX, a variant featuring a 15% wider center hull. This modification, as noted by NauticExpo, significantly increases interior volume and load-carrying capacity, making it a preferred choice for owners intending to spend more time aboard. The F-9 series also includes the "Center Cockpit" (CC) sibling, most commonly seen in the Corsair F-31 production line, which separates the living quarters into a main saloon and a private aft cabin located behind the cockpit.

Popular Mentions & Media

The F-9A and its production sibling, the F-31, have maintained a high profile in the multihull community for decades. The F-31 variant was named Australian Sailboat of the Year in 1992, and the design's reputation for seaworthiness was bolstered by several documented Atlantic crossings. Reports in Latitude 38 have historically tracked the F-boat community, highlighting the design's ability to handle heavy weather, provided it is sailed with the vigilance required of an ultralight multihull.

Known Issues & Buyer’s Checklist

Prospective buyers of an F-9A must account for the variability inherent in amateur-built vessels. While the design is structurally robust, the execution of the build is the primary variable.

• Bulkhead Bonding: In early or aggressively sailed models, the secondary bonding of the forward bulkheads to the hull can show signs of fatigue or separation due to the "pounding" forces encountered in heavy seas.
• Folding System Hardware: The folding struts and their associated pins and bolts are critical components. Inspect for elongated bolt holes, hairline fractures in the aluminum struts, or signs of electrolysis if the boat was kept in salt water.
• Deck and Ama Core: Many F-9As were built using balsa or foam cores. Use a phenolic hammer or moisture meter to check for soft spots, particularly around stanchion bases, daggerboard trunks, and the beam-to-ama attachment points.
• Daggerboard Trunk: Ensure the trunk is structurally sound and that the daggerboard itself moves freely without excessive play, which can indicate internal wear of the trunk liners.

Community & Resources

The F-boat community is one of the most organized in the nautical world. The Farrier Marine (now managed via technical archives) and the "F-Boats" technical groups are the primary repositories for build manuals and modification histories. Owners often reference the F-31 technical wikis and Corsair Marine’s historical documentation, as many components are interchangeable between the custom F-9A and the production Corsair models.

The Verdict

The F-9A remains a benchmark for the "Performance Cruiser" category, offering a rare blend of trailerability and genuine speed.

Pros:

• Exceptional Speed: Capable of double-digit speeds in light air and 20+ knots in a blow.
• Versatility: The folding system allows for easy trailering and cheaper slip fees.
• Beachability: Daggerboard and kick-up rudder designs allow for nose-in beaching.

Cons:

• Build Variance: As a plans-built boat, quality depends entirely on the original builder’s skill.
• Weight Sensitivity: Performance and safety can be compromised if overloaded with cruising gear.
• Interior Space: While functional, the interior is narrow compared to modern cruising catamarans or monohulls.