South African Onyx 10.5 revives interest in compact cruising cats

Small cruising catamarans under 40 feet have been largely absent from major manufacturers for nearly two decades, but the arrival of the Onyx 10.5 offers fresh momentum for sailors who want compact, capable cruise platforms. Built by Onyx Marine in South Africa, the 34’4” design brings a number of original solutions that aim to pack liveaboard comfort into a manageable footprint.

The Onyx 10.5 stands out visually with raised side-decks and a coachroof supported by inverted struts, a look that signals modern thinking as much as it does structural intent. Inside, the layout favors contemporary owner comfort: the hulls open onto sugarscoops that house two large, owner's-style double cabins, a configuration more commonly found on larger cats. Sail area is about 936 sq ft (87 m²), providing the power necessary for cruising performance in a hull that displaces 12,125 lbs (5.5 t).

Propulsion takes a different route from conventional twin diesels. The yard fitted one central Vetus motor rated at 42 hp that drives two propellers through a hydraulic transmission. That single-engine, twin-prop arrangement cuts complexity and could reduce maintenance and fuel costs, while still offering redundancy from a propulsion perspective. Fuel capacity is 92 US gal (350 l) and water capacity is 132 US gal (500 l), sensible tankage for coastal or short-term bluewater cruising.

There are practical caveats. Draft is shallow at 3’1” (0.95 m), useful for shoal cruising, but visible bridgedeck clearance looks modest and will need verification on the first test sails to ensure comfortable downwind pitching and wave slam avoidance. At a beam of 22’10” (6.95 m), the Onyx 10.5 is wide enough to give interior volume yet compact enough for tighter marina berths and the lower cost of berthing compared with larger cats.

Pricing positions the build as a serious option: €361,740 ex-tax. For sailors comparing the narrow field in this size bracket, the Onyx 10.5 joins the Broadblue 346 as one of the few sub-40ft production cats currently available since models like the Aventura 34 were discontinued.

The immediate impact is practical: owners who wanted full-size owner cabins but balked at maintaining a 40-plus-foot cat now have another choice. Dealers and brokers should expect interest from coastal cruisers, couples and smaller crews who prize manageable systems and modern ergonomics.

The takeaway? The Onyx 10.5 aims to punch above its length with clever layout and a simplified propulsion concept. If bridgedeck clearance proves adequate on sea trials, this could be the tidy, user-friendly cat many of us have been waiting for, compact enough to make slips and budgets easier, but roomy enough to actually cruise in comfort.