Initially marketed to amateur builders as a set of comprehensive plans, the Trailertri 18 was constructed primarily using marine plywood and epoxy. Farrier envisioned an affordable, easily trailerable alternative to the sluggish, heavy monohull day sailers of the era. Compared to its contemporary competitors—which were mostly pocket cruisers or heavy trailer-sailers—the Trailertri 18 prioritizes speed, level sailing, and beachability.
Because these vessels were owner-built, the interior fit-out varies wildly. The layout is Spartan, offering just enough space inside the main hull for minimalist weekend accommodation for two or three close adults. The joinery is entirely dependent on the skill of the original builder, generally consisting of painted plywood bulkheads and simple timber trim. There is no headroom to speak of, but the massive net area between the hulls acts as an expansive open-air deck, effectively moving the living space outdoors.
Sailing Performance & Handling
At the helm, the Trailertri 18 delivers a highly responsive, dinghy-like experience with the safety of a stable, wide-beam multihull. The boat carries a fractional sloop rig that is easily managed from the cockpit. With a displacement of 1,698 pounds and a sail-area-to-displacement ratio of 17.53, the trimaran possesses a generous power-to-weight ratio. It accelerates quickly in light air, bridging the gap between high-performance beach catamarans and traditional cruising monohulls. The displacement-to-length ratio of 153.48 indicates a moderately light displacement hull that can easily transcend its theoretical hull speed, transitioning into a plane under the right downwind conditions.
While traditional monohull metrics like the capsize screening formula of 4.7 and comfort ratio of 4.47 suggest a highly dynamic, tender, and motion-heavy vessel, these formulas fail to capture the physics of a trimaran. The Trailertri 18 derives its stability from its extreme fourteen-foot beam and high-buoyancy amas rather than a heavy lead keel. The result is a boat that sails with very little heel, drastically reducing physical fatigue on the crew during a long day on the water.
Equipped with a pivoting centerboard, the boat draft ranges from a deep 3.74 feet with the board down to a mere 1.18 feet with the board raised. This makes the Trailertri 18 an exceptional tool for shallow-water exploration, allowing owners to slide over sandbars, sail into estuaries, and nose directly onto the beach for family picnics.
Known Issues & Triage
As a plan-built wooden boat, the primary threat to any surviving Trailertri 18 is rot, particularly in areas where freshwater can pool or where raw wood was left unsealed by the builder 2. Prospective buyers must perform a thorough moisture inspection of the main hull, decks, and amas. The ama compartments are inherently difficult to ventilate, and builders who neglected to install proper inspection ports or drain bungs often left internal bulkheads vulnerable to dry rot. Probing structural joints, bulkheads, and the areas surrounding the chainplates with a moisture meter is a mandatory triage step.
The folding mechanism and its associated hardware require close engineering scrutiny. Early iterations of Farrier's folding system utilized hinged aluminum brackets bolted through the wooden deck beams. Over decades, these mounting points can experience severe stress, leading to hairline cracks in the surrounding fiberglass-and-plywood laminate or corrosion of the metal components. Furthermore, galvanic corrosion between stainless steel bolts and the aluminum brackets can cause fasteners to freeze in place. The original wooden folding beams must be checked for splits, cracks, or soft spots, and the lower aft sides should ideally feature drain bungs to prevent water accumulation inside the beam cavities.
Modernization & Upgrades
Owners looking to modernize a Trailertri 18 can unlock significant performance and safety gains by updating the rigging and hardware. Replacing older, heavy stainless steel standing rigging with modern synthetic lines like Dyneema sheds valuable weight aloft, further improving the boat’s stability and responsiveness. Retrofitting the mainsail luff with low-friction sail slugs instead of the traditional bolt rope greatly simplifies single-handed hoisting and reefing from the cockpit.
Because weight is the enemy of multihull performance, the heavy lead-acid batteries of the past should be swapped for lightweight lithium-ion (LiFePO4) chemistry. A single, modest lithium battery can power the boat's running lights and basic instruments at a fraction of the weight of a traditional marine battery. While many original hulls were equipped with small gasoline outboards, modern owners are increasingly converting to lightweight electric outboards. An electric motor eliminates fuel smell, reduces maintenance, and preserves the boat’s overall balance and sailing characteristics. Finally, replacing or fabricating worn folding bracket plates out of high-grade stainless steel or modern composite materials ensures the folding mechanism remains secure for years to come.
The Verdict
The Trailertri 18 is a historically significant, highly rewarding pocket multihull that offers sparkling sailing performance, unmatched trailering versatility, and shallow-water freedom. However, because it was built from plans by home crafters, it is a model best suited for owners who enjoy hands-on maintenance, wooden boat restoration, and the distinct character of classic epoxy-and-plywood construction.
Pros
- Revolutionary folding system allows for effortless trailering and standard slip berthing without dropping the mast.
- Fast, responsive, and flat-sailing performance that easily outpaces monohulls of a similar era.
- Shallow draft and pivoting centerboard permit easy beaching and shallow-water gunkholing.
- Large net areas provide excellent open-air deck space for day sailing.
Cons
- Varied build quality due to its amateur, plan-built origins.
- Susceptibility to wood rot in poorly ventilated or unsealed hull and ama compartments.
- Extremely limited interior headroom and Spartan cabin accommodations.
- Age-related wear on vintage aluminum and wood folding mechanism brackets.
