Linear Lift System

Straight-path travel for flat and angled transoms
The defining characteristic of the Linear Lift System is its guide rail: a vertical track mounted directly to the transom, along which the lift arms travel without lateral deflection. The platform descends in a straight line, maintaining a constant distance from the hull surface throughout the full stroke. This eliminates the swing radius that rotation davits require — a radius that, on a flat- stern catamaran, would collide with the hull itself.

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The guide rail accommodates transom angles from 0° (fully vertical, typical for sailing catamarans) to 30° (inclined aft, common on power catamarans and some motorboat designs). The mounting hardware is configured for each transom profile individually, ensuring the rail sits flush against the hull surface regardless of angle. Because the travel path is constrained by the rail, the platform position is repeatable within millimetres — every launch and recovery places the tender at exactly the same point, which simplifies crew operations and reduces the risk of hull contact during handling.

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Engineered for hull forms that rotation systems cannot serve
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Rotation lift systems rely on a pivoting arm that sweeps the platform through an arc. This works well on monohulls with a curved transom, where the arm can rotate outboard and clear the hull. On a catamaran — where the transom between the two hulls is a flat vertical surface and the hulls themselves bracket the platform on both sides — a rotation arc has nowhere to go. The linear system solves this structural limitation by eliminating the arc entirely.

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Beyond catamarans, the system serves centre-cockpit motorboats, trawler yachts, and expedition vessels where the stern profile is box-shaped or vertical rather than contoured. On these hull forms, the available space behind the transom is typically narrow: there is little room for swing-out arms or extended lever linkages. The linear guide rail requires minimal depth behind the mounting surface, making it the most space-efficient davit architecture for constrained stern installations. The platform carrier is height-adjustable and inclinable, allowing precise alignment with the deck surface to eliminate gaps and height differences at the boarding edge.

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Higher yield strength for demanding load configurations
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The standard material for all Linear Lift System components is AISI 316L stainless steel (1.4404), electropolished for corrosion resistance and surface hygiene in permanent saltwater environments. For installations with higher structural demands — heavy tenders, extended stroke lengths, or vessels operating in extreme conditions — the lift arms and critical load- bearing brackets can be specified in Duplex stainless steel 1.4462.

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Duplex 1.4462 combines the corrosion resistance of austenitic steel with roughly double the yield strength: approximately 450 MPa compared to 220 MPa for standard 316L. This means structural sections can be designed with less material while carrying the same load, reducing the weight of the lift arms without compromising safety factors. For a catamaran builder counting grams per component to stay within displacement targets, this is a measurable advantage over systems built entirely from standard austenitic grades. The choice between 316L and Duplex is made during the engineering phase based on load calculations and the shipyard’s structural requirements.

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