22 One-Design Class Sailboat Handbook 



The keel in a small sailboat is built as an integral part of the hull and 

 has a ballast weight attached to its bottom. There are two basic types 

 of keels: fin keel and deep, or full, keel. The majority of the keel sloops 

 described in Chapter 6 are of fintype. In the simplest form, this type of 

 keel has the appearance of a dagger centerboard that has been lowered all 

 the way and fixed in place. Generally it's an iron casting with a cigar- 

 shaped bottom, actually as ballast. But, the fintype keel can't be lowered 

 or raised. Whatever its distance below water, that's the minimum depth 

 of water in which you can sail. Most fin keels, even on small craft, re- 

 quire a draft of at least two feet. 



The deep or full keel is usually triangular shaped when viewed from 

 the side. The apex of the triangle is at the bow and the base is aft. Lead 

 or iron ballast, in the form of a casting, is attached at some point along 

 the bottom of the keel. This type of keel has a great deal of lateral-plane 

 area, is very strong, and is very stable due to the fact that ballast is posi- 

 tioned low. Actually, because of heavy ballast of both types of keel boats, 

 they have immense stability and this helps to keep them on proper sail- 

 ing lines. The chief disadvantages of this type are that they will sink if 

 swamped and are exceedingly difficult to transport. 



If you have a choice between a sailboat with a keel and one with a 

 centerboard, it should be remembered that each is a good craft if used 

 under the circumstances for which it was designed. In an area where the 

 water is uniformly deep, the keel boat is generally preferable. If the water 

 is thin, the centerboard type is the best craft. The latter is also the better 

 if extreme speed is desired. Suppose two boats are built to the same lines 

 and equipped with the same sail plan. On one, a centerboard is a board; 

 in the other a keel is installed. The craft with the centerboard will be 

 the faster on all points of sailing except to windward, while the greater 

 underwater area of the keel boat will allow it to point higher into the 

 wind and make less leeway. Before the wind, the centerboard boat can 

 be raised, thus reducing the wetted surface. When coming about, the 

 centerboard craft will be somewhat quicker because it has less area of 

 lateral plane and because what area it does have is well centered. In a 

 boat having a centerboard, it must be adjusted for the different points 

 of sailing, as well as the sail's sheets. This, of course, isn't necessary with 

 a fixed keel. 



