Average Weight of Sailboat Keels (5 Most Common Types)
The keel weight of sailboats differs greatly and can range anywhere from 200 to 12,000 pounds based on the keel type and boat length and use. The average keel weights are not readily available on the internet, so I've compiled an extensive list based on offline research and reasoning from fundamentals below.
Most sailboats carry around 35-45% of their total weight in their keel. An average 35-foot cruiser weighs 15,000 pounds, which means the keel will weigh between 5,000-6,000 pounds on average. Small sailboats carry approximately 200-1,000 pounds in their keel.
However, the keel weight is very dependent on the keel design. Different keel designs require different ballast weights. It's all determined by the ballast to displacement ratio, which I'll explain below.
How Much Does a Sailboat Keel Weigh?
There are three ways to explore sailboat keel weight:
- based on sailboat size
- based on keel design
- based on popular sailboats
Below, I'll list the average keel weight based on all three factors, starting with sailboat size.
Keel weight based on sailboat length
| Size | Average length | Average weight | Average keel weight |
|---|---|---|---|
| Small sailboats | 15 to 20 feet | 400-2,500 pounds | 160-1000 lbs |
| Medium sailboats | 21 to 25 feet | 2,500-5,000 pounds | 1000-2000 lbs |
| Cruising sailboats | 27 to 32 feet | 7,000-12,000 pounds | 2800-4800 lbs |
| Large sailboats | 35 to 40 feet | 12,000-30,000 pounds | 4800-12000 lbs |
However, the total required weight is not just determined by sailboat weight, but also by sail area and the length of the keel.
Keel weight based on keel design
Since the amount of ballast is very dependent on the boat length and indented sailing conditions, we have to make a lot of assumptions to pair each keel design to an average weight, making it an impractical comparison.
The difference in average keel design weights is mostly based on different standard applications of these keel designs. However, it is possible to show the effects of keel design on ballast weight requirements, by comparing the same class of boats with different keel designs.
Keel design weight differences
The examples below are the average keel weights on similar 40-foot cruising sailboats, using different keel designs, allowing for a comparison in ballast requirements based on design alone:
- Full keel: 8,000 lbs
- Bulb keel: 6,000 lbs
- Fin keel: 5,000 lbs
- Wing keel: 5,000 lbs
As you can see, the deeper the keel runs, the lower the required ballast will be. Bulb keels look like fin keels but are shorter, using more ballast to enable a shorter design.
Full keels and modified full keels run less deep, thus requiring more ballast to provide the same righting moment. Fin keels and wing keels run the deepest, reducing the amount of ballast needed.
Leeboards are unweighted, as are daggerboards most of the time. Centerboards can either carry ballast or not, based on the sailboat model.
Keel designs from heavy to light
We can also compare keel design weights based on their expected relative weight. So let's say we have a sailboat and we just switch out the keel, how heavy would each keel be relative to the others? From heaviest to lightest:
- Modified full keel
- Full keel
- Bilge keel
- Bulb keel
- Fin keel
- Wing keel
- Centerboards
- Daggerboards
- Leeboards
Keel weights of popular sailboat models
| Boat model | Displacement | Keel Design | Ballast in pounds |
|---|---|---|---|
| Jeanneau S.O. 409 | 16,424 | Wing keel | 4,982 lbs |
| Bavaria Cruiser 40 | 19,139 | Wing keel | 6,131 lbs |
| Beneteau Oceanis 41 | 18,624 | Fin keel | 5,071 lbs |
| Hanse 415 | 19,621 | Bulb keel | 6,395 lbs |
| Catalina 385 | 15,500 | Fin keel | 5,200 lbs |
| Hunter 39 | 18,501 | Fin keel | 6,027 lbs |
| 1956 Bounty II | 18,800 | Full keel | 8,000 lbs |
Using the ballast to displacement ratio
The ratio used to describe the weight of the keel compared to the total weight of the sailboat is called the ballast to displacement ratio. You can use this ratio to get a general idea of the properties of a boat, but it does have major shortcomings.
For an overview of how to use the ballast to displacement ratio, I recommend reading my article on it.
Does Keel Material Matter?
While keels can be made out of several materials, it shouldn't affect the amount of weight you use. The ballast should be equal either way. Keel materials depend mostly on available space and budget. If you have restrictions on space, you need a heavier material to get the same amount of ballast. If you have restrictions on budget, you typically use something lighter. Having restrictions can be somewhat of a double bind.
How Do Sailboat Keels Work?
In short, a sailboat keel's weight is used to to increase displacement and lower the center of gravity, while its surface is used to increase wetted surface. This helps to stabilize the boat, but also provides directional stability. For a more detailed explanation on how sailboat keels work, I recommend reading this article.
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Comments
Chris Jokinen
I am guessing the information here is for monohull boats, what about Catamarans and Trimarans?
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