Keels

I was just thinking the other day about the various ways in which the word "keel" is used in present day language. On sailboats, there are "full" keels, "fin" keels, "swing" keels, "bilge" keels, "wing" keels and "wing-bulb" keels, just to name a few of them. Those keels can be made of wood, fiberglass, steel, cast iron and "who knows what" else.

On power-driven boats, there is much less talk of keels than on sailboats. One reason is that powerboat keels protrude so little by comparison to sailboat keels. Powerboats don't rely on a keel nearly as much as sailboats do for maneuvering or maintaining a heading. A keel is of little importance to most power boaters. If you asked the average power boater what kind of keel was on their boat, they probably wouldn't know.

On the other hand, a sailboat is subject to such a degree of "side slip" when under sail, that the relationship of the keel to the hull becomes very important. Generally, a deeper or fuller keel will result in more heeling and less sideways motion (slip). But, the deeper or fuller keels pose more of a navigational challenge in shoal waters. Our focus today will be on sailboat keels.

In days of old, when knights were bold, when men were made of steel and ships made of wood, a keel was defined quite differently than it is today. It began its role as the lowest principal timber of a wooden ship extending the full length of the vessel. To the keel, the stem, ribs and sternpost of the vessel were attached. On steel ships, the keel was the lowest continuous line of plating.

Boy, have things changed! Today's technology has altered the role of the keel dramatically. Given that the marine recreational market is dominated by fiberglass construction, present day boats rely much more on the structural strength of the "skin of the vessel" and less on the "skeleton" or frames. What we "refer" to as the keel on a sailboat these days rarely runs more than 20% of a vessel's length.

Given the "abbreviated" nature of today's keels, many of our structural needs regarding the hull are met elsewhere. Our preferences for a particular type of keel are no longer based on structural criteria, since with the latest technology we can have structural integrity with any of the keel options. Keels are chosen much more for performance, or perhaps to minimize our draft.

We want a full keel on a sailboat if we want it to "point" more, or to be better at "going to wind." The full keel also gives us a lower center of gravity. Along with that goes more weight and a deeper draft. Those are two things that we will sometimes shy away from.

When you add it all up, our preference for one type of keel over another is really a matter of weight, performance, draft, or cost. If you take a stroll through a boatyard, you'll see a variety of keels. It must be for the same reason that Baskin Robbins has 31 flavors. So, just like many words that we've used over the years, so too evolves the definition of a keel!

Until next time, I wish you clear skies, fair winds, and calm seas!