Last week I got the chance to hear designer Mark Mills (he drew the King 40 and Summit 35, among others) discuss the relative merits of a bowsprit with asymmetric spinnaker vs. a traditional spinnaker on a pole.
As a J/Boat guy, I’m fully onboard with the advantages of a sprit, specifically the ease of use, lower crew requirements, and increased fun factor. But Mills took a more scientific look at the advantages of either configuration under IRC in specific wind ranges.
A traditional spinnaker can operate like an asym with the pole all the way forward, however the sail by necessity has less area. With a longer luff length, an asym flying from a bowsprit will offer roughly 15% more sail area on the same boat – and IRC is pretty forgiving of this increased downwind sail area.
The final analysis? According to Mills, an asymmetrical kite on a sprit will be at an advantage at or below 12 kts under IRC; above 12 kts, the versatility of a traditional pole comes into its own. As always, individual results may vary; consult your yacht broker/sailmaker/tax advisor before making any changes to your sailing diet.
As a J/Boat guy, I’m fully onboard with the advantages of a sprit, specifically the ease of use, lower crew requirements, and increased fun factor. But Mills took a more scientific look at the advantages of either configuration under IRC in specific wind ranges.
A traditional spinnaker can operate like an asym with the pole all the way forward, however the sail by necessity has less area. With a longer luff length, an asym flying from a bowsprit will offer roughly 15% more sail area on the same boat – and IRC is pretty forgiving of this increased downwind sail area.
The final analysis? According to Mills, an asymmetrical kite on a sprit will be at an advantage at or below 12 kts under IRC; above 12 kts, the versatility of a traditional pole comes into its own. As always, individual results may vary; consult your yacht broker/sailmaker/tax advisor before making any changes to your sailing diet.
Now THAT'S a spinnaker! (King 40 at KWRW)
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