Design and Construction
The 20.5 is a folding trimaran whose floats ride on sliding aluminium beams, collapsing the beam from a maximum 4.50 m to a folded 2.48 m width that sits below the road gauge for trailing behind a normal hatchback. The central hull runs 5.95 m with 5.90 m floats, and each float holds 930 litres of volume for stability. A tulipped hull shape deflects spray, and the builder describes the lines as modern and sporty. Two construction paths exist: a standard solid laminate hull just over 500 kg, or a resin-infused central hull dropping the weight under 500 kg. The centreboard is offset to port to keep the middle of the boat clear, and the boat carries EC Category C for five persons at 425 kg and Category D for seven at 550 kg. Writing in Yachting Monthly, the reviewer noted the builder stands apart from Dragonfly, Corsair and Tricat with more stripped-down multihulls at attractive prices.
Rig and Handling
The rig is a fractional sloop available with a standard or Sport version; both share the same mast height, though the Sport adds a square-top mainsail for appreciably more area — 24 m² upwind and 42 m² downwind against 21 and 34 standard. A carbon or wing mast is optional, and hardware is mostly Harken with Sélden spars. The boat is easy to rig and handle, and the mast can be raised singlehanded. Under test sail, the 20.5 proved taut and responsive, reaching 12.5 knots on a beam reach in 12–15 knots of wind and holding 7 to 8.5 knots upwind, where it sailed straight past a 49 ft monohull. Tacking was positive with minimal leeway, and with the centreplate down it was surprisingly manoeuvrable and felt rock solid. A 6:1 mainsheet and 2:1 jib sheet let a pair of sailors manage her easily.
Accommodations
Below, the narrow hull beam makes things cosy: a seat sits either side, with stowage beneath and to either side of the companionway and space for a chemical toilet under the aft berth. The finish is simple and uncomplicated, largely to save weight, and Yachting Monthly called it slightly stark. Above decks the trampolines each side give vast lounging space and can take a tent for extra sleeping, while the cabin itself offers seating and room for a couple to stretch out. Compared with a monohull of similar length, accommodation is necessarily less, but the open multihull platform trades enclosed volume for liveability on deck.
Versions and Ownership
Astus offered a leisure model for gentle family sailing and a sports version using a vacuum-system central hull to satisfy regatta sailors. The boat is economical with minimal maintenance, garage-storable, and nomadic between waterways thanks to its trailer and retractable floats. With a maximum 4.5 kW (6 HP) outboard and a 2.5–5 hp recommended specification, running costs stay low. Multihulls World judged the 20.5 to present many convincing arguments starting with a reasonable budget, delivering pleasure and speed in simplicity.
The Verdict
The Astus 20.5 is a cleverly engineered pocket trimaran that turns the compromises of tiny cruisers into advantages: it folds for the road, sails with real pace, and keeps ownership light. The sparse interior is the price of portability, but the deck lifestyle and trailering ease are genuinely distinctive.
Pros
- Folds to 2.48 m beam for trailing behind a hatchback and garage storage
- Lively performance — 12.5 kt beam reach, 7–8.5 kt upwind in testing
- Simple, light construction with low maintenance and minimal cost
- Singlehanded rigging with optional carbon or wing mast
Cons
- Stark, narrow below-decks accommodation with less than a same-size monohull
- Rigging process could be simplified
