Bieker Moth

Bringing you ever closer to lightning speed.


When a group of top navel engineers, designers and builders come together with very few design restrictions, something quite remarkable is born. Meet the Bieker Moth, sailed by world champions.







Length overall           3.355 m

Beam                         2.250 m

Max. luff length        5.185 m

Max. mast length     6.250 m

Hull weight                Unrestricted, general weight range 10-20kgs

Rigged Weight          as little as 26kgs

Sail area                    8.25m

Optimum skipper weight     60-80kgs




The Build


Producing consistency into everything we build is our goal.  We strive to make sure that the platform (hull and wings) we supply are the best possible and very consistent. Every part is checked, weighed and recorded so we have a complete build record for each boat.


Sailors can also apply their own expertise to develop their boats further.


Spare parts can be fitted easily and means that upgrade parts can be adapted to existing boats.


The Moth is full of ever developing parts so it is an ongoing project for us to apply the concept as each part develops.



The Hull


The centreline-joined hull is built from pre-preg carbon fibre on a nomex core. The hull is a comparatively high-volume displacement shape, with a rocker profile for easy low ride handling and un-sticky take-off characteristics.







The Deck


Designed with a deck-sweeping rig in mind, a fairing panel on the deck aft of the mast enables the sail to be sealed onto the deck.  This feature reduces drag, makes the sail more efficient and allows the boat to get the most from the end plate effect.




Wing Beams and Solid Wings


Using minimal tramp area, the platform concept minimises aerodynamic drag and heeling moment.


Stiff single piece wing beams located in rebated deck sockets maximise effective beam when heeled to windward through a curved, high angled shape.


The wing beams are high modulus pre-preg carbon, constructed as a single piece using bladder moulding. They are designed to eliminate the need for compression struts and unnecessary joins. This rigid wing frame also reduces windage and streamlines the platform.


The solid wing option reduces aero drag and makes the boat faster to tack and gybe.  This wing also enables sailors to impart kinetic energy into the boat during tacks and gybes.






Internal Take-ups and Controls


The take-ups from the control lines have been designed to run inside the solid wing which further reduces drag. This concealed control system along with the control line configuration makes for a clean deck layout.







The foils are made from high modulus pre-preg carbon with foam cores in the verticals for incredible stiffness. Using state of the art production techniques, the single piece foils are cured at high temperature and pressure with precision alloy tools. The foils come faired, finished and ready to race.




The Team


The team behind the Bieker Moth capitalises on a diverse background in high performance boats, from the America’s Cup to i14s, foiling kites, 18’ skiffs, Moths and Olympic classes.


  • Scott Babbage Project Manager
  • Paul Bieker Naval Architect
  • Riley Dean Design Engineer
  • Leopold Fricke FEA engineer
  • Hal Youngren Foil Section Designer
  • Nico Rousselon CFD engineer
  • David McDiarmid- Mackay Boats Director




The low drag verticals have less area. They are shorter and also narrower in some areas. As a result they are also lighter.

Area and section shape. More area has more drag, but it also lifts the boat sooner in lighter winds. Section shape varies the amount of lift and drag. For heavier air foils the emphasis is more on reducing drag. On lighter air foils lift becomes more important, but not if it increases drag too much. It is always a compromise which is why development will always continue in the quest for more lift with less drag.

Solid wings have some handling advantages and aerodynamic advantages.

Soft wings are lighter.

For bigger sailors, the trade off is often in favour of having a lighter platform, whereas lighter sailors can take the aero gain of the solid wings.


To get the most aerodynamic gain, the deck faring should match or be a little longer than the foot length. Theoretically, longer is better, but it is also hard to sail with. It is no problem to cut down the length of a deck fairing to match your sail should you change at a later date.


The Hi-Top box is needed if you want your solid wings to fit into a box with your boat. Alternatively you can use the standard box and package the wings separately if you don’t travel a lot.

Air freight is charged by volume, so it costs less if you use the smaller box and pack the wings separately. However, this also has its risks, so we recommend the Hi-top box if you are regularly freighting your boat to reduce the chance of your wings being damaged or lost.

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