Choosing a Centerboard or Fixed Keel Sailboat

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Centerboard or Fixed Keel?

Centerboard and Keel Sailboats
© Tom Lochhaas.

You need to consider many different questions when deciding what kind of sailboat is best for you. Start with this article on how to buy a sailboat

Depending on the general size range of the sailboats you may be interested in, you may need to choose between fixed-keel boats and centerboard (or swing keel or daggerboard) boats. This article will help you choose which is best for your needs.

As only a very general rule, most sailboats over 20-something feet have fixed keels. Most sailboats under 15 feet or so have centerboards. But there is a wide range of boats from 12 to about 25 feet with either a fixed keel or a centerboard. For example, in this photo, ​the boat on the left has a fixed keel, while the boat on the right, of about the same size, has a centerboard.

If you are shopping for a sailboat in this range, you should understand the differences between these fundamental types of keels.

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Fixed Keel Sailboats

Full Keel
© Tom Lochhaas.

Virtually all large racing and cruising sailboats have a fixed keel. A keel is needed to keep the boat from being blown sideways at all points of sail except downwind. A keel also provides weight low under the water to lower the boat’s center of gravity below the waterline, which is needed so that the boat bobs back upright if knocked over by wind or waves.

Sailboats have many different types of fixed keels, such as full keels (see photo) and fin keels. If you decide a fixed keel boat is best for your sailing purposes, consider also which type keel best meets your needs.

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Centerboard Sailboats

Centerboard sailboat
© Tom Lochhaas.

On centerboard sailboats, the centerboard functions like a keel to keep the boat from being blown sideways. (All sailboats need a keel of the board for this reason: the narrow, flat surface of the board or keel produces little drag when the boat moves forward but resists motion sideways.)

The centerboard usually hangs down below the hull from a pivot at one end. It can be raised by pulling a line that swings the centerboard up into a centerboard trunk along the center of the boat, as shown in the photo.

Some small boats, like a Sunfish, have a removable daggerboard rather than a centerboard. The daggerboard has the same function, but rather than swinging down, it is inserted like a blade down through a slot in the hull to protrude like a thin keel below the hull. A swing keel is another term used for a type of keel that like a centerboard can be raised.

A centerboard may or may not be weighted. If the centerboard is weighted, then it also provides weight low in the water, like a keel, to help keep the boat upright (although not as much weight as a fixed keel can supply). If the centerboard is not weighted, like the fiberglass centerboards of many small sailboats, then sailors must keep the boat upright by positioning their own weight on the upwind side of the boat. 

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Benefits and Disadvantages of Fixed Keel and Centerboard Sailboats

Centerboard vs Keel Sailboats
© Tom Lochhaas.

Fixed keels and centerboards each have their own benefits but also disadvantages. When deciding what type of boat to buy, be sure you have considered these differences:

Advantages of a Fixed Keel:

  • Provides the most ballast to resist capsizing and ensure recovery from a capsize
  • More effective at preventing leeway (sideways movement of the boat)
  • Crew do not have to position body weight to prevent capsizing (see photo)
  • No centerboard moving parts to break or jam

Disadvantages of a Fixed Keel:

  • With deeper displacement, the boat cannot enter shallow water
  • The boat is heavier for its size (usually an issue only when trailering)
  • With deeply fixed keels, the boat may not fit on a trailer at all (25 feet is typically the largest trailerable fixed keel sailboat) - requiring the inconvenience and expense of a boatyard for launching, haulout, and storage

Advantages of a Centerboard:

  • The centerboard can be raised to decrease displacement to allow the boat into shallower water – and it should swing up and back if it hits the bottom when sailing with it down
  • The centerboard can be raised for faster downwind sailing
  • The centerboard can be partially raised if needed to provide better boat balance
  • Most centerboard boats can be trailered and easily launched and hauled out on boat ramps (larger centerboard boats may require deeper ramps)

A popular trailerable centerboard sailboat is the MacGregor 26, which with its water ballast has the advantages of centerboard boats but not all the disadvantages.

Disadvantages of a Centerboard:

  • Provides no (unweighted board) or less (weighted board) ballast, compared to a fixed keel, to resist capsizing and ensure recovery from a capsize
  • Less effective than a larger fixed keel at preventing leeway (sideways movement of the boat)
  • The centerboard trunk takes up space in the boat’s cockpit or cabin
  • The centerboard pivot and control line involve moving parts and can jam or break

Finally, some historic crafts have leeboards instead of centerboards; these boards, mounted outside the hull on both sides, can be pivoted down like a centerboard to resist leeward motion. And some sailboats have fixed keel-centerboard combinations, which provide ballast and prevent leeward motion even when the centerboard is up but also provide the option to attain less leeward motion sailing upwind when the board is down.e a centerboard to resist leeward motion. And some sailboats have fixed keel-centerboard combinations, which provide ballast and prevent leeward motion even when the centerboard is up but also provide the option to attain less leeward motion sailing upwind when the board is down.