We Found a Boat Made of Rocks and Plastic Bottles!

Along the sunlit Mediterranean coastline of Canet-en-Roussillon, where the rugged Pyrenees meet the Golfe du Lion, naval architecture is undergoing an ecological transformation. It was from this historic port in southern France that the crew of Sailing Helios originally commenced their full-time bluewater journey three years ago. Returning to the harbor to evaluate the latest advancements in sustainable multihulls, Vincenzo and Georgia investigated a revolutionary concept: an offshore cruising catamaran built from mined volcanic basalt rock and recycled plastic bottles, powered by electric propulsion, expansive solar arrays, and hydrogeneration.

Founded in 2018 by Olivier Kauffmann and his son Gautier in close collaboration with renowned multihull architects Christophe Barreau and Frédéric Neuman, Windelo Catamaran was created to bridge the divide between sluggish production charter cats and delicate racing multihulls. Joined by communications director Julie and test skipper Louis, Vincenzo and Georgia examined bare hull laminates on the factory floor before stepping aboard a newly commissioned Windelo 54 Yachting edition for a thorough liveaboard inspection and open-water sea trial.

Volcanic Rock and Recycled Plastic: Eco-Composite Naval Architecture

Touring the composite workshop in Canet-en-Roussillon, Occitanie, France, Vincenzo and Georgia of Sailing Helios observed how the Windelo Catamaran shipyard constructs hulls from volcanic basalt fiber. Drawn from mined volcanic basalt rock that is melted and extruded into continuous filaments, basalt fiber demands tenfold less energy and water to manufacture than standard E-glass. When vacuum-infused into structural sandwich panels alongside biosourced epoxy and recycled plastic bottle foam, basalt fiber delivers 19 percent greater mechanical stiffness than fiberglass while reducing manufacturing emissions by roughly 47 percent.

The core material supporting the sandwich structure tells an equally impressive recycling story. Windelo utilizes high-density closed-cell structural foam derived from shredded post-consumer polyethylene terephthalate (PET) plastic bottles. Following two years of intensive mechanical stress testing with French universities, the shipyard verified that recycled PET foam delivers outstanding shear strength, compression resistance, and moisture impermeability without delamination risks common in traditional PVC foams.

In its raw woven state, basalt fabric displays an elegant bronze luster, but transforms into a lustrous pitch-black finish resembling carbon fiber once infused under vacuum with epoxy resin. This enhanced stiffness allows the vessel to maintain structural integrity and high performance in demanding sea states without adding laminate thickness or deadweight. Furthermore, basalt fibers separate cleanly at end-of-life, establishing a recyclable composite lifecycle that conventional fiberglass cannot match.

Shipyard Craftsmanship and Monocoque Hull Engineering

During their production walkthrough in Canet-en-Roussillon, Occitanie, France, Vincenzo and Georgia of Sailing Helios noted the intensive handcrafting required for each Windelo Catamaran incorporating basalt fiber laminates. Constructing each yacht demands 17,000 to 18,000 hours of skilled craftsmanship. Shipwrights hand-laminate all primary structural bulkheads and hull-to-deck joints using continuous basalt fabric and epoxy rather than relying on glued butt joints, creating a rigid, squeak-free monocoque platform designed for rugged ocean passages.

Weight control and structural integrity reinforce one another throughout the build. To keep a 50-foot catamaran light at roughly eleven tonnes, all interior furniture modules are crafted on-site from lightweight wood laminates bonded over recycled PET foam cores. The factory floor in Canet-en-Roussillon builds multiple models—including the 50, 54, 51 Sport, and 55 Sport—on the same standardized 24-hour vacuum infusion tooling, optimizing industrial efficiency while preparing for upcoming 58 and 62-foot flagship catamarans.

Safety engineering is embedded directly into the lower hull architecture. Sacrificial crash boxes protect the bows, accompanied by airtight buoyancy compartments below the forward sail lockers and aft of the machinery spaces. These sealed volumes ensure the catamaran remains positively buoyant even if multiple compartments are punctured. Similarly, the central daggerboard trunks are heavily laminated into floor stringers, utilizing intentionally sacrificial foils that shear off cleanly on high-speed impact without breaching the watertight hull boundary.

Forward Cockpit Helm Ergonomics and Seamless Living Spaces

Aboard the Windelo 54 Yachting in Canet-en-Roussillon, Occitanie, France, Vincenzo and Georgia of Sailing Helios analyzed how the Windelo Catamaran merges basalt fiber composite construction with an ergonomic forward cockpit and panoramic living area. Positioning the helm station inside the coachroof enclosure at the mast base concentrates halyards, reefing lines, and sheets at electric winches, enabling effortless single-handed maneuvering while sheltering the watchkeeper from harsh weather.

Standing at the centralized wheel, the watchkeeper enjoys an unobstructed forward line of sight through opening windshields to the sails, bows, and sea. An adjacent reclining daybed allows off-watch partners to rest comfortably within arm’s reach of the helm during nocturnal passages. Overhead opening hatches provide instant ventilation and clear vertical sightlines to the mainsail trim, while repeating navigation multifunction displays keep key telemetry visible across the saloon.

A monumental tilting aft door lifts smoothly into the overhead structure, transforming the enclosed saloon, galley, and aft terrace into a single flush-level living pavilion. The domestic-grade galley provides seven meters of countertop space, induction cooking, an electric oven, a double-drawer refrigerator, and a dishwasher. In the port hull, the owner suite boasts a queen berth framed by an expansive corner window, an integrated daggerboard walkthrough, a quiet navigation desk, and a spacious forward bathroom with a walk-in shower stall.

Electric Propulsion, Solar Photovoltaics, and Hydrogeneration

Inspecting the electrical telemetry in Canet-en-Roussillon, Occitanie, France, Vincenzo and Georgia of Sailing Helios reviewed how the Windelo Catamaran pairs lightweight basalt fiber hulls with twin electric inboard motors and self-sufficient renewable energy. The silent propulsion system eliminates diesel exhaust, vibration, and routine motor maintenance, drawing power from an extensive lithium battery bank recharged by rooftop solar and hydrogeneration.

The coachroof supports a 6,000-watt (6 kW) flush-mounted solar photovoltaic array capable of generating 20 to 30 kilowatt-hours of clean power daily in Mediterranean conditions. Even during late afternoon hours with low sun angles and mainsail shadows covering half the panels, the system showed a net positive energy balance. This renewable harvest allows cruisers to operate reverse-cycle air conditioning, induction cooktops, and watermakers at anchor indefinitely without firing an engine.

Under passage, the electric propulsion drives seamlessly switch into hydrogeneration mode. Water rushing past the folding propellers while sailing between six and ten knots spins the electric motors, generating hundreds of watts to replenish the lithium bank. For extended calms or transoceanic passage-making through doldrum belts, a compact DC diesel generator serves as a range extender, providing over 1,100 nautical miles of motoring range at six knots across 183 continuous running hours.

Sea Trial Under Sail in the Golfe du Lion

Venturing out into the Golfe du Lion from Canet-en-Roussillon, Occitanie, France, Vincenzo and Georgia of Sailing Helios sailed the Windelo Catamaran to test its basalt fiber performance in open waters. In light breezes of seven to eight knots, the multihull accelerated to seven knots of boat speed. Symmetrical vertical daggerboards and a balanced mast-forward sail plan provided sharp hydrodynamic lift without noticeable leeway.

Acoustic refinement under sail proved exceptional. By bonding foam-backed cabinetry directly to the basalt composite bulkheads, the shipyard eliminated the creaks, groans, and structural racking common to traditional production catamarans. Down in the owner cabin while sailing at seven knots, the only sound was the soothing, rhythmic lapping of water against the slender hull.

Handling sail controls was equally straightforward. With the boom positioned at a safe, accessible working height over the coachroof, crew members flaked the mainsail easily into the lazy bag while secured by dedicated jacklines. Weighing roughly 12.8 tonnes light, the Windelo 54 moves effortlessly in light airs where conventional yachts must motor, while offering proven offshore capability that has seen sisterships clock speeds of up to 19 knots in ocean swells.

Windelo Eco-Catamaran Telemetry and Material Composition

To summarize naval architecture findings in Canet-en-Roussillon, Occitanie, France, Vincenzo and Georgia of Sailing Helios compiled technical telemetry detailing the Windelo Catamaran, basalt fiber laminates, and electric propulsion systems. The following table highlights structural dimensions, sustainable materials, and auxiliary power ratings gathered during the shipyard inspection and sea trial.

Frequently Asked Questions

To assist bluewater cruisers and multihull enthusiasts evaluating sustainable naval architecture, Vincenzo and Georgia of Sailing Helios compiled answers regarding the Windelo Catamaran, basalt fiber composite performance, and electric ocean passagemaking assessed during their technical review in Canet-en-Roussillon, Occitanie, France.