Jet Ruban Bleu Yacht

The design came from Gilles Ollier at Multiplast, a yard with deep experience in high-performance sailing composites and record-breaking ocean racers. The brief was simple in theory: create a lightweight, extremely stiff hull capable of sustained speeds above 55 knots across the North Atlantic. In practice, this meant pushing composite construction into territory it had never occupied in powerboats.

Jet Rubin Bleu used a carbon sandwich structure with a Nomex honeycomb core, 100 mm thick, skinned with 4 mm carbon laminates on each side. The laminates were laid using pre-impregnated carbon fabrics with a high fibre content, supplied by Hexcel, whose client list came from the aerospace industry. The goal was stiffness, low weight and dimensional stability under extreme loads.

Unlike smaller prepreg parts, the hull could not be cured in a conventional oven. Heat had to be applied indirectly, and vacuum consolidation was used across the structure. In theory, the process matched best practice. In reality, the project exposed a critical weakness: the adhesive system used between the carbon skins and the honeycomb core shared too close a viscosity with the resin in the prepreg. When heat was applied, the bonding adhesive was drawn away, leaving widespread delamination throughout the hull.

The fault emerged late, during internal cutting of the structure. Large sections of the hull had effectively become unbonded laminates. Dismantling the boat would have ended the programme, so the team cut the hull open along the chines and keel, re-bonded the core manually using Araldite, applied vacuum again and physically restrained the structure with ratchet straps. It was crude and risky, buteffective. The hull held.

Early Trials and Structural Issues

Initial trials delivered headline speeds above 55 knots. However, the hull had been designed for flat water. During heavy-sea running, especially in the Channel and off Brittany, repeated impacts exposed weaknesses unrelated to materials alone. Windscreens fractured. Localised cracking appeared where rigid reinforcements conflicted with natural hull flex. In several incidents, water entered the engine room after structural damage.

Multiple repair cycles followed. Reinforcement laminates were added. Structural elements were stiffened locally, sometimes at the expense of global load paths. Each fix solved one problem and risked creating another.

The Atlantic Attempts

Two Atlantic attempts ended short of success. In one case, Jet Rubin Bleu was ahead of record pace south of Newfoundland when hull skin failure allowed water ingress, forcing abandonment. Inspection confirmed renewed sandwich separation in impact zones. The structure had not failed from lack of strength, but from fatigue and shock loads outside its intended operating envelope.

In hindsight, the project’s core weakness was not materials or ambition, but a mismatch. A powerboat designed to operate continuously at extreme speed requires offshore racing experience at every level: design detail, piloting technique and operational judgement. Jet Rubin Bleu combined elite sailing expertise with a discipline that plays by different rules. High-speed offshore powerboats do not forgive momentary misjudgement, nor do they tolerate structures that are “just about strong enough”.

Aftermath and Legacy

Jet Rubin Bleu never took the Blue Riband. In 1992, the Italian-built Destriero crossed the Atlantic at an average of 59.4 knots. Jet Rubin Bleu did, however, leave a clear legacy. It proved that composite powerboat structures could reach unprecedented stiffness-to-weight ratios. It exposed the limits of transferring sailing-boat thinking directly into offshore powerboats. And it remains one of the most ambitious single-purpose speed machines ever built in France.