: As the article below shows, it is possible for

: One thing that stability graphs cannot do is tell you how many more
: times stable one kayak vs another will "feel".
: Stability in this context is too subjective.

: I make this point because I am familiar with kayaks that have
: stability curves that are very close to one another but
: "feel" quite different. Classic stability curves are
: not that well correlated with how a kayak "feels"

: It is also difficult to even define what it means to say that
: something will feel "four times" as stable as
: something else.

: It is rare to find a 22" non-radical design that will have a
: stability curve that is not considerable less than a non-radical
: 24" design. As the article referenced discusses, ends that
: are "fuller" make the curves more "stable".
: Waterline width is much more the key than overall width.
: Waterline width is the measurement that you should consider most
: important in trying to prejudge a kayaks stability. 24"
: inch width accomplished by marked flare above the waterline in a
: boat that is 22" at the waterline will feel much closer to
: a 22" boat without flare (at least on flat water)/

: The fact is that many people find 22" kayaks quite comfortably
: stable. It is not radically thin. Yet others will find that same
: kayak to be unstable. In considering yourself, I would recommend
: paddling a couple of 22" designs to get an understanding of
: how that "feels" to you before committing to a
: building such a craft.

You are quite right about the feeling of stability being a very subjective thing. Saying that one kayak would feel four times as stable was largely my way of trying to use simple layman's terms and avoid technical terms. I should have said that according to the formula used to calculate stability, one kayak had four times as much righting moment at about 20 to 25 degrees as another kayak the same width.

Of course the formula used to calculate stability just gives a rough guide for the purposes of comparison. As you have said, waterline width is more significant than maximum width when it comes to primary stability and it is usually primary stability rather than secondary stability that less experienced paddlers use to judge how stable a kayak feels. I mentioned the importance of the hull cross section and just one of the ways that affects stability is that different shapes with different amounts of flare will change the waterline width.

As well as those obvious things that we have mentioned, stability will be affected by other things like the paddler's build and the height of the seat. A tall male with broad shoulders will destabilize a kayak much more than a short female who is more pear shaped. I have read that some designs of kayak can have their stability halved by raising the seat just one inch. However, most sea kayaks would not be affected quite that much. Then, as you have said, different paddlers can have quite a different perception of the stability of the same kayak.

Even looking just at the waterline width of a kayak is not a particularly reliable indication of stability. Most people are surprised at how different two designs with the same waterline can feel and the formula confirms that there can be a significant difference in the righting moment.

I think we might both be trying to make the same important point. Stability is quite a subjective thing and certainly can't be judged by simply looking at the maximum width of the kayak.