Use Of A Skeg
Many paddlers have have asked, "exactly what is the skeg for" and "how can I use it"? It's use is simple but often misunderstood. In this article we'll go over what a skeg is, how and when to use a skeg, and how it relates to the wind!
The kayak skeg is not a rudder. It is not a steering device.
It is a trimming device.
With a skeg you can add variable amounts of lateral (sideways) resistance to the stern of your boat. That is a good thing, here's why...
Kayak with Rudder Deployed
A rudder is a steering device.
Kayak with Skeg Down
A skeg is a trimming device.
The skeg is used to trim your kayak in winds and to correct for unbalanced loading.
Its thoughtful use allows the paddler to track (go in a straight line) in the variable conditions of wind and in various loading configurations of your kayak.
A kayak will tend to turn into the wind, this is called weather-cocking.
This is caused by the difference in pressure between the bow and stern of your kayak.
As you paddle forward, water flows past your kayak.
At the bow, this flow is laminar as it follows the shape of your hull, gradually this flow becomes turbulent, and near the stern the flow separates from your hull completely and forms eddies.
Wind
Because of the laminar flow near the bow, the pressure is the highest, and the kayak 's ability to move laterally (sideways) is the least.
Because of the turbulence near the stern, the pressure is the lowest, and the kayak's ability to move laterally is the greatest.
Thus, the wind's effect will be greatest at the stern (rear).
The wind will blow your stern downwind, pointing your bow upwind,
this is weather-cocking.
Upwind: Skeg up / Downwind: Skeg Down
The skeg, when lowered into the water, adds resistance to lateral movement at the stern.
Since the kayak will want to turn upwind (given a neutrally trimmed boat, see discussion below) no influence is needed when paddling upwind, so skeg up.
When paddling downwind, you will need full use of the skeg, so skeg down.
In various other directions of wind, you can vary the amount of skeg for best effect.
Trim Your Kayak with Your Load
The wind's ability to move the stern downwind is also affected by how you have your boat loaded.
A kayak loaded evenly front and back is a neutrally trimmed boat. The effects of wind will be as described above.
However, a kayak with more of a load in the stern, is stern heavy trimmed. This will help reduce the wind's effect at the stern. However, you might find your bow being blown downwind.
In Summary:
With a skeg you can add variable amounts of lateral resistance to the stern of your boat to compensate for effects of wind and loading.
Additionally, a skeg will help a rudderless kayak glide straight.
This is very useful let's say, when both hands are off your paddle and you're trying to take a quick photo while you're gliding.
So, for this it's skeg down, but remember to go skeg up as you continue paddling forward or you will wonder why your ability to turn is hampered.
