Remarks :This 1981 Formosa 51 staysail ketch is a well-proven and highly regarded bluewater cruising yacht, designed by William Garden and built by Formosa Boat Building Co. Ltd in Taiwan. A full-keel, long-waterline heavy-displacement design, the Formosa 51 earned a strong reputation for seakeeping and offshore capability during the 1970s and 1980s, and this example has been comprehensively updated between 2023 and 2025 to bring her systems, rig, and accommodation to a high standard. She is offered for sale as a practical and well-found liveaboard bluewater ketch, ready for immediate use. The programme of work carried out under current ownership is extensive and methodical: a fully overhauled engine with new exhaust, steering, and cooling systems; all-new sails on both masts including furling main, furling mizzen, furling staysail, and a new yankee; refurbished and extended main mast and a new mizzen mast; 900W of solar with an MPPT controller and six new gel batteries; all 14 seacocks replaced with Trudesign fittings; new water, fuel, black water, and grey water tankage; and a hydraulic bow thruster and windlass installation. The teak interior was professionally refinished in 2023. Highlights Listed below but included in Full Specs: Designed by William Garden; long-keel offshore ketch Ketch rig with all-new sails — furling main, furling mizzen, furling staysail, and hank-on yankee (2023–2025) Refurbished and extended timber-boxed main mast; new timber-boxed pine mizzen mast (2023) Perkins 6.354, 125hp diesel — valves and injectors overhauled; new exhaust, cooler, and steering cables (2024–2025) 900W solar array with MPPT controller (2023) 6 x 160Ah gel battery bank (2023) Hydraulic bow thruster — new piping and header tank (2023) Hydraulic windlass — new engine-mounted pump and hoses (2023) All 14 seacocks and through-hull fittings replaced with Trudesign (2024) 1,200-litre water capacity — tanks fitted (2023) 650-litre fuel capacity — new 300-litre stainless steel tank (2023) Two electric heads (2023) B&G touchscreen chartplotter at helm (2023); Raymarine VHF with AIS (2025) Hydraulic autopilot control unit at helm (2024) Full solid teak interior professionally refinished in satin varnish (2023) 33kg Rocna anchor with 100m x 12mm chain (2023) Fixed bimini and matching boom tent with foredeck extension (2023) New black Dyneema guardrails with safety nets all round (2024) Five-cabin layout with upper saloon and wheelhouse BROKER'S REMARKS The Formosa 51 is one of the better-known names in classic bluewater cruising — a William Garden design that built a strong following through the 1970s and 1980s for its solid construction, seakindly motion, and practical liveaboard accommodation. This 1981 example has been in the hands of an owner who understands what a vessel of this type requires and has invested consistently to bring her up to a high standard. The work carried out since 2023 is substantial and well-targeted: structural seacocks, rig and sails, engine, tankage, and electrical systems have all been addressed. For a buyer looking for a capable offshore ketch with the major work already done, this is a vessel that repays careful inspection. Below decks, the accommodation is generous. Five berths across four cabins, an upper saloon and wheelhouse with chart table, and a well-fitted galley with standing refrigerator and dining table make for a comfortable and practical liveaboard environment. The solid teak interior, professionally refinished in satin varnish in 2023 with headliners in oyster white, is in good order and gives the boat a warm character below that is difficult to replicate in a modern production vessel. With 900W of solar, a large gel battery bank, new tankage, hydraulic bow thruster, and a complete sail wardrobe across both masts, this Formosa 51 is well set up for extended Mediterranean passages and offshore use. Early inspection is recommended.Accommodation :ACCOMMODATION The Formosa 51 offers generous liveaboard accommodation across four cabins and a large upper saloon/wheelhouse. The interior is finished throughout in solid teak, professionally refinished in satin varnish in 2023, with headliners painted in oyster white. Bronze portholes and hatches have been polished. New cushion and mattress covers were fitted throughout in 2023. Headroom is approximately 2m in the saloon — generous for a vessel of this era and type. LAYOUT The layout comprises a forward cabin with bunk berths and a sink, a second cabin with a pull-out double berth, a lower saloon with a dining table that drops to form a large double berth, and a master cabin aft with a large double berth. A very large upper saloon and wheelhouse features a chart table, a second dining table with seating that drops to form a large double, and the inside helm position. Two heads compartments are fitted. DOMESTIC The galley is equipped with a 12V compressor refrigerator/freezer and a new stainless steel sink (2023), with a large dining table opposite. Two heads compartments are fitted, each with a new electric toilet (2023). The forward heads includes a small bath in the shower compartment.Inventory :NAVIGATION Chartplotter: B&G touchscreen at helm (2023) Autopilot: Raymarine control unit at helm (2024), operating original hydraulic pump and steering VHF radio: Raymarine with AIS capability (2025) Chart table: Large chart table in upper saloon/wheelhouse DECK Windlass: Hydraulic, engine-mounted pump — new pump and hoses (2023) Main anchor: 33kg Rocna with 100m x 12mm chain (2023) Second anchor: 50kg CQR — spare Kedge anchor: 25kg — mounted on second bow roller Mooring lines: Set of long lines (60m each); full set of mooring warps Fenders: 6 new long fenders (2025); 2 large ball fenders; 2 smaller fenders Guardrails: New black Dyneema with full safety nets all round (2024) Passerelle: Large lifting passerelle — hoisted to mizzen mast Deck wash: Salt water deck wash (2025) SAFETY Seacocks: All 14 seacocks and through-hull fittings replaced with Trudesign composite fittings (2024) Life raft: 6px CANVAS Fixed bimini: Custom-built, fitted (2023) — 900W solar array mounted atop Boom tent: Large, with zip-on foredeck extension, matching canvas (2023) TENDER Optional extra MISCELLANEOUS Two Seldén self-tailing winches — supplied, not yet fitted Original davits — removed but included Set of long mooring lines (60m each) LED engine room lighting (2023) HISTORY This Formosa 51 ketch was built by Formosa Boat Building Co. Ltd in Taiwan in 1981 — one of the later examples of a model produced between 1972 and 1984 from the drawing office of William Garden. The Formosa 51 was designed as a serious offshore cruising vessel, with a full long keel, solid GRP construction, and a heavy-displacement hull that has since carried numerous owners on ocean passages. Under current ownership the yacht has undergone an extensive programme of work between 2023 and 2025. Major works include a full engine overhaul with valve and injector rebuild and new Perkins head gaskets (2025), a new custom stainless steel exhaust system (2025), replacement of the engine cooler (2024), new steering and gear cables (2025), a new larger alternator (2023), and overhaul of both Capilano hydraulic steering pumps with seal replacement (2024). All 14 seacocks and through-hull fittings were replaced with Trudesign composite fittings in 2024. The hydraulic bow thruster and windlass received new piping, a new engine-mounted pump, and new hoses in 2023. The rig was comprehensively updated in 2023: the main mast was refurbished and extended, a new timber-boxed pine mizzen mast was fitted, and a complete new sail wardrobe was installed across both masts including a furling main, furling mizzen, furling staysail, and new hank-on yankee. New stainless steel mast base rigging plates were fitted in 2025. New black Dyneema guardrails with full safety nets were installed in 2024. The electrical system was updated with a 900W solar array with MPPT controller and six new 160Ah gel batteries in 2023. New water, fuel, black water, and grey water tankage was installed in 2023. The solid teak interior was professionally refinished in satin varnish with oyster white headliners in 2023, and new cushion and mattress covers fitted throughout. Further details of ownership and maintenance history are available on request. Mechanical :CONSTRUCTION Builder: Formosa Boat Building Co. Ltd, Taiwan Designer: William Garden Year: 1981 Hull material: GRP (solid fibreglass below waterline) Hull type: Full long keel Rig: Staysail ketch Construction: Solid GRP hull; 1¼-inch fibreglass below waterline DIMENSIONS LOA: 15.49m (50ft 10in) — per manufacturer specification (see note below) LWL: 12.06m (39ft 7in) — per manufacturer specification Beam: 4.29m (14ft 2in) — per manufacturer specification Draft (max): 1.88m (6ft 2in) — per manufacturer specification Displacement: 23,587kg (52,000 lbs) — per manufacturer specification Ballast: 5,443kg (12,000 lbs), cast iron — per manufacturer specification Sail area: 116.5m² (1,254ft²) — per manufacturer specification MECHANICAL Engine: Perkins 6.354, 125hp diesel inboard Engine works: Valves and injectors overhauled; head gasket and associated gaskets replaced using genuine Perkins parts (2025) Exhaust: New custom stainless steel self-cooling exhaust system (2025) Engine cooler: Replaced with new gaskets (2024) Alternator: New larger alternator fitted (2023) Steering cables: New steering and gear cables (2025) Hydraulic steering: Two Capilano hydraulic steering pumps — seals replaced, systems refilled (2024); operating helm above deck and in wheelhouse Bow thruster: Hydraulic — new piping and hydraulic fluid header tank (2023) Windlass: Hydraulic, engine-mounted pump — new pump and new hoses (2023) Drive type: Shaft drive Engine hours:5000 PERFORMANCE Cruising speed (motor): Approximately 6–7 knots Hull speed: Approximately 8.4 knots Sail area / displacement ratio: 14.47 Comfort ratio: 55.3 (per manufacturer data — notably high for offshore use) TANKAGE Fuel: 650 litres (143 gallons) — steel tank 350 litres; new stainless steel tank 300 litres (2023) Water: 1,200 litres (264 gallons) — tanks fitted (2023) Black water tank: Fitted (2023) Grey water tank: Fitted (2023) Salt water deck wash: Fitted (2025) ELECTRICAL Battery bank: 6 x 160Ah gel (2023) Solar: 900W array mounted on fixed bimini frame (2023) Solar controller: MPPT charge controller Shore power: To be confirmed LED engine room lighting (2023) LED strip lighting throughout (2025) 230V fans (2025) 12V USB charging points — above and below deck (2023/2025) RIGGING Rig type: Staysail ketch Main mast: Timber-boxed aluminium — refurbished and extended (2023) Mizzen mast: New timber-boxed pine (2023) Mast base rigging plates: New stainless steel (2025) Mainsheet and kicker brackets: Additional stainless steel brackets (2024) Kicker: Dyneema kicker with Seldén 4:1 pulley system Running rigging: Black Dyneema throughout Guardrails: New black Dyneema with full safety nets all round (2024) Winches: Two large Barlow headsail winches; one large Barlow mainsheet winch; two Seldén self-tailing winches (supplied, not yet fitted) SAILS Mainsail: Good condition (2023) Mizzen: furling mizzen (2023) Staysail: furling staysail (2025) Furler needs repair/replacement Yankee: hank-on yankee (2023) Heavy weather staysail: Spare — supplied