Efficiency indeed! Launched on Friday 3 June 2005, this boat won the Genève-Rolle race on the Saturday, in a breeze. Her success was followed by winning the Bol d'Or, the Transmajestic and the 6 heures de Nernier. Four wins in a row for her first season in class 2 of the ACVL (the rating rules currently applied on Lake Geneva): what a start!

For this project, commissioned by a private jet pilot, a client with an excellent appreciation of foil behaviour, we were offered the opportunity of pushing foil optimisation towards finer and more aggressive profiles than we might normally employ. Among our objectives were low surface area, high-aspect ratios, a lengthy 3D milled steel fin with trim tab, and advanced foil sections. Moreover, use of an Angle of Attack display (AOA), taken from a Learjet 45, allows our 'test-pilot' helmsman to accurately record valuable target data when trying to optimise upwind performance in particular.
The ACVL rating rule limits the hull length only and leave girths, freeboards or other constraints unrestricted, so we are in a good position to pursue our development work on volume asymmetry while heeling, creating waterlines comparable to asymmetric wing sections which work with the foils to resist sideforce. The hull may not be such an efficient ‘foil’, but we must try to push things forward wherever possible!

The deck layout was the third main issue of this design. By opening up the cockpit almost completely laterally, keeping the minimum sidedeck for the (optimum) seven crew to sit comfortably and to hike.

Safety is, as ever, always taken into account and we carefully checked the waterline level at 90° of heel and ensured that all the openings remained above that level, which guarantees that no water gets in during such bad manœuvres (and they do happen!).

Spinnakers and foresails will be manoeuvred on foredeck through an America's Cup-style sliding hatch, custom made in light composite. Talking of sails, the sail plan was optimised in close collaboration with Jean-Marc Monnard of Europ'Sails, using carbon-fibre high-stability fabrics.

Hull and deck construction revolve around ensuring sufficient I-Beam stiffness, with plentiful use of carbon unidirectional both along the sidedecks and running along the hull bottom. However, the principal construction uses a laminate of glass/epoxy/PVC foam, which allows us to keep the price down to a relatively manageable 200'000 to 230'000 euros depending on specifications.

Articles:

04276_article_NautismeRomand_juillet2005.pdf (1189 Kb)

04276_article_Seahorse_may2005.pdf (762 Kb)

More informations:

www.chantiernaval-luthi.ch

www.europsails.ch