As a kayaktester I look at the behaviour of seakayaks in respect to whether they show lee- and/or weathercocking.
Last week I had an email-discussion with Axel about leecocking of seakayaks.
Axel wrote at a certain moment that he feels that most seakayaks show leecocking when the wind starts exceeding 6Bft.
We had both a different theory to explain this.
Axel explained it as a difference between paddling fast (in less wind) and slower (much wind): As a result of your speed the pressure-points of the wind on the side of your kayak changes resulting in lee-or weathercocking.

My explanation of the mechanism is that, when you are paddling with a normal balanced kayak in this kind of wind, there are waves. And when you pas a wave your bow is likely to be lifted a little bit in the air.
At that moment the wind can push the bow aside. That's just it!: this is the leecocking in strong winds. The stronger the wind and the higher and/or steeper the waves are the stronger this effect will be.

Honestly I can not understand completely why the pressure points should change in respect to the speed.
What I can imagine, to explain the different behaviour in relation to the speed, is that the higher the speed is, the higher the impact is with which you pierce your kayak through the waves. The higher the impact, the less the effect of the wind in gripping the bow will be. Or may be that you go more through the waves at higher speed. While paddling over the waves at low speed, offering more bow-surface to the wind, will result in leecocking.

Another effect, causing leecocking, can be that the kayak is balanced wrong and that it will leecock already without waves. Like in the situation that you are paddling with the variable skeg fully down at a moment when you don't need it.
However until now I did not encounter a kayak like this: these would be badly designed kayaks.

So all this leaves me with the leecock-effect in waves. When I noticed leecocking like this, mostly this happens when you are paddling against the wind under an angle of approximately 15-90°.

Although I agreed with Axel on the fact that most kayaks will show leecocking, to some extend, in strong winds, I found, during the last years of testing, that there are differences in this behaviour between different seakayaks.

These differences have to do with the ability to correct them on leecocking and the degree of paddling-experience you need to perform the corrections.

Therefor I divided seakayaks into 3 global groups, which I describe underneath for "normal-wind-situations":

1. manoeuvrable kayaks that show slight weathercocking without using the skeg
2. manoeuvrable kayaks that show neutral behaviour in wind without using the skeg
3. good tracking kayaks that show slight weathercocking in wind without using the skeg

All kayaks have the tendency to leecock under the windy conditions as described, but with a kayak from group-a) it is very easy, in between two waves, to go back to the original course because the kayak responds quickly on corrections. This works because of the manoeuvrability and because, when the bow is back in the water again, it can start weathercocking again which helps in steering against the wind. It could well be that paddlers in a kayak like this, never experienced leecocking because they correct it automatically. Like I did myself in my AnasAcuta; very clearly a group-a)-kayak.

With a kayak from group-b) it is already a little bit more difficult to maintain your course because the kayak does not help you by weathercocking, steering against the wind again.

With a group-c)-kayak it could well be that you are not back on your original course before you hit the next wave and your bow is blown away even further; the more wind the more extreme this effect will be. In that case you have to work very hard and you will have to use al kind of tricks and techniques to prevent being blown of course completely.
If the kayak has also a neutral behaviour in wind without skeg, it will be even harder to keep control over her.

The effect, as described above, will get worse (for all the above described groups of kayaks) when your kayak has a very bulky bow or a very long bow: the wind will have more impact on the bow while blowing it aside. This

Another issue that will worsen the leecocking-behaviour is an integral skeg on the kayak. This skeg performs as a kind of turning point at the after-end of the kayak, giving you the task to turn the kayak against the long lever-arm between your sitting position and the turning point of the kayak; about half a kayak length which requires quite a lot of force. Paddling for correction, it will not help very much if you edge the kayak because, in waves, you will probably not be able to lift the skeg above the water level for making the kayak more manoeuvrable.

The fact that I am writing this essay is that I don't like correcting for leecocking in heavy weather because you have to edge to the downwindside of your kayak, bringing yourself in a more unstable and more delicate situation.

Therefor, personally I like, for safe and comfortable paddling, a kayak of group a): a manoeuvrable kayak that slightly weathercocks when you have the variable skeg out of use. I choose “slightly weathercock” because, given a situation that the skeg is damaged, the kayak should be manageable without the variable skeg as well. Further, I would not give the kayak a bulky bow, nor an integral skeg (nor a rudder that reacts the same as an integral skeg)

When you are in need of better tracking don't choose a good tracking seakayak, but you better can work on your technique and getting better experienced or you drop the variable skeg about 1cm. This situation is, to my humble opinion, much better instead of correcting for leecocking, which I regard as the most undesired situation in seakayaking.

I hope these thoughts can be adapted by kayak-designers as a guideline once!