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The design, materials and construction of the Columbia 30 deliver a light – but very strong - boat. We use a carbon-fiber keel fin keel, rather than (for instance) a steel fin, to deliver maximum strength and stiffness while minimizing weight (our carbon keel spar weighs only 26 pounds. A steel keel spar would weigh about 360 pounds). Moreover, a retracting keel typically requires bulky, heavy interior structures to accommodate the retraction. Our Carbon Fiber Superstructure is low-profile, with minimal intrusion to the cabin, distributing all keel, mast and rigging loads throughout the entire hull.
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| A U2 spy plane shows off |
With this in mind, it's worth examining the shape of the keel fin itself. The highly efficient keel shape generates the maximum lift with minimum drag, again similar in effect to the wing of an aircraft. The most efficient wing shape is long and narrow. Think of the wings of a glider, or of the U2 spy plane. Their long and narrow wings generate the highest lift to drag ratio. The design, materials and construction of the Columbia 30's keel fin allow it to be long and narrow, as well as stiff and strong. This translates directly into less drag and more speed.
With the factors of weight and form in mind, the shape of the keel bulb has been carefully considered. Ideally, as much weight as possible is distributed as low as possible in order to make the vertical center of gravity lower and thus increase the righting moment. This creates a faster boat, simply because the more vertical a boat sits, the more efficiently the sail plan can harness the wind.
A fast, safe and efficient bulb shape requires a dense metal to achieve maximum weight in the smallest volume possible, and a shape that has the maximum possible volume within the least possible surface area and drag. This shape - in its purest form - is a ball. Our torpedo shaped bulb is simply that – an elongated ball. Similar in design to the shape of a modern submarine – viewed from the bow, either shape is immediately recognizable.
That said, a ball creates turbulence when pushed through the water…the beavertail shape at the aft end of the bulb reduces this turbulence and drag and maintains the speed advantage generated by its basic shape.
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