Lee Cocking

I know what weather cocking is, but could someone explain to me what lee cocking is? What conditions cause it and what does the boat do during lee cocking? How do you combat it?

Thanks.

Weathercocking vs. leecocking
Think of “cocking” as meaning “turning into”. So, Weathercocking turns into the wind, leecocking to the lee (or out of the wind). Heavily skegged boats, or stern-locked boats will lee cock in heavy weather, which is bad. If you can’t turn upwind, I hope your destination is downwind. Most boats are built with at least a bit of weathercock into them for this reason. Hard edging will get you back upwind, but maintaining it can be a struggle. Trimming the boat load further forward will help as well.



Jim

lee cocking

– Last Updated: Jul-08-08 1:11 PM EST –

is the tendancy of your boat to go downwind when you are trying to head into the wind--it can be so pronounced in a heavy breeze and in a rough sea that you actually get "pinned" and can only go down wind or abeam or across the wind. It generally happens more freqently to higher volume boats which are being paddled empty with nothing in the hatches to ballast them. The wind will catch the bow of the boat and push it downwind or to leeward--hence the name lee cocking.

It can be reduced or minimized by two ways, first by loading the boat, usually with camping equipment, sometimes with bottled water, to ballast it. This makes the boat heavier and less vunerable to be pushed by the wind. I myself feel uncomfortable putting extra ballast in a boat---camping equipment is fine if tightly packed but loose ballast would have a tendancy to shift, creating other handling problems---some paddlers use fixed ballast but again that makes me nervous.

The other, and in my opinion, better way is to use techniques to correct leecocking--these would include using a serious of forward sweeps on the downwind side followed by a bow rudder, or bow draw on the upwind side to turn the bow into the wind---once in the wind you can use forward sweeps and bow rudders to keep it there. Also if you use a skeg, pull it up when trying to go into the wind. A deployed skeg will increase the tendancy of a boat to lee cock. Finally under no circumstances should you use a ruddering stern brace or stroke to turn the bow into a strong wind---the ruddering stern brace has a tendancy to slow the boat down and raise the bow slightly, both of which will result in lee cocking.

Can also move the seat forward
In addition to jonsprague’s suggestions, you can also alter the trim by modifying seat position. After reading Jonathan Walpole’s comments and test results using an unloaded Explorer LV with light paddlers–and after a brief test of my own–I glued in my foam seat about 1" forward of the “standard” position.



I figure I can always play with weight distribution when carrying camping gear, so I want the boat to weathercock when paddling unloaded. Paddle strokes, edging, and a deep skeg are all tools that are still available to me to deal with the weathercocking.

Underlying assumption
Rereading the replies so far, I realized that all have described how to compensate for leecocking but nobody has stated what starts it in the first place.



If the boat leecocks, that means the stern end is relatively fixed in the water compared with the bow. Hence, the comments about changing trim to “unfix” the stern. Whichever end is getting blown downwind, you put more weight onto/toward it to “fix” it down in place relative to the other end.



BTW, when I first started paddling, I heard “weathercocking” used as the term to describe both weathercocking (bow moving upwind) and leecocking (bow moving downwind).

Also note
that it’s not just about the hull and the loading but also about the conditions. If your stern is buried in a trough and your bow is up in the air where the wind can grab it, you’re going to tend to swing parallel to the wind. Timing your strokes to where you are in relation to the waves helps, as does paddling a shorter, lower volume hull (pushing a ski into brisk tradewinds in the bow quarters is kind of a bitch).

If this “weathercocking” applys to …

– Last Updated: Jul-10-08 12:08 PM EST –

........ canoes , then I think understand why it was exceptionally difficult to make the 180* turn from running into the wind , to running with the wind recently .

The conditions were kinda extreme (windwise) , 20+ steady . Had made the crossing from the leeward side and now running the windward shore of a large mountain reservor with rising terrain each side . So far all has been into the wind .

This is our 3rd day out and also our last before turning and going home . We (tandem) decide we will push into the right fork of the reservor , just up ahead , and see how much more of this we feel up to .
As we round the bend (leaving the windward shore cover) into the right fork , the wind speed seemed like it doubled , had to be 30 or more . We pushed hard into it and quickly became very tired of trying to make headway . The whitecaps were spraying us and we said to each other , had enough yet ??

So this is it , time to do a 180* !!

We initiated to the left , and poured on the steam . Not nearly enough paddle power to keep the bow coming around . Jambed in full and hard rudder , it wasn't powerful enough to have more than 1/2 control . We leaned in hard (first to the right , then the left), bow paddler kept digging into the turn . We were skewing at a 45* downwind with everything we could muster and closing on the shore fast from about 300' out , the bow just would not come around enough to run straight down wind . At any point if I let off some rudder , the canoe's bow would swing back to the right and try to end up broadside to the wind , even with the bow paddler digging and sweeping .

Fortune was on our side , we were blown back around the bend as we closed into the shore line , the wind slowed back to 20+ in there , and the turn was completed . Happy paddlers we took a crossing again under full control . All through the event , I was laughing myself silly , she was praying , and I understood I was just almost outmatched by the wind for the first time .

After reading these post I think I understand better now . She (in the bow) is a good 30 lbs. heavier than I . My bow was dug in to much because I was the light end (the stern) .

If this is the case , I will be more prepared in the future to unload the bow and/or heavy the stern .
Sound correct ??


You got it.
The higher the wind speed or the more pushy the water, the more pronounced the effect becomes. I had the opposite happen to me a couple years ago when I demoed a tandem canoe with my then 9yo daughter in the bow. Lee cocked so bad, I had to paddle backwards to get to the put-in. I tried to kneal amidship, but just wasn’t froggy enough to lean it over with her on board. Being able to trim weight underway would have been a boon.

design, trim, movement
A well balanced boat will lay to the wind more or less perpendicular when at rest.

With a rudder or skeg fully deployed, the boat at rest will lay to with the bow downwind, sometimes as much as parallel to the wind.

That is a hint- if your boat is loaded down poorly(a lot of gear in one end of a solo boat, or a tandem canoe/kayak with paddlers of very dissimilar weights, the boat will behave the same way.

This can become a basic test for your trim- if the wind is blowing, stop paddling and observe where the boat comes to rest relative to the wind direction. If it is more or less perpendicular, great. If not, watch out.



The other component is boat movement. When a boat move through the water, the center of lateral resistance moves foreward. Thus, winds abeam will create a force that causes the boat to turn upwind. This can be compensated for by skegs, rudders, stroke/edging tactics, and even overall strategy. While it is tempting to load a kayak to adjust trim that will counteract this, this leaves the kayaker with fewer options if the wind (or kayaker) changes direction.



Some boat designs have a skeg-like aft keel (some Eddylines, the Nordkapp HM, for example) in an attempt to reduce weatherhelm (a preferred term for weathercocking) at normal paddling speeds.



Of greatest note is this- since most weatherhelm is caused by the boat’s forward movement, the boat’s manuverability can be controlled by the paddler. If a boat has a strong tendency for leehelm when moving forward…this is either a poor boat design, or a poor loading job…you can be in deep trouble. It is exceedingly hard to control a boat with strong leehelm You are simply at the mercy of the conditions.



Try this. Load a bunch of filled water jugs into the bow of your kayak. When paddling forward, notice that the kayak becomes beast and is hard to keep going straight. But also notice that one of the reasons is that the stern is silly responsive to your steering strokes. Now, load the stern reaaally heavy. Hmmm, it goes straight now! Cool, you think…until you try to turn it, and nothing happens.







Karl

And why kayaker should canoe

– Last Updated: Jul-09-08 9:39 PM EST –

One of the things a learning canoeist should undergo is paddling in easy (Force 3) wind, and simply getting off the seat and moving around the boat when paddling.

The canoe is the ulimate skeg! Just because they have seats, doesn't mean you have to sit there. Soloing a tandem design is an example. The way too often mistake is to sit in one of the seats (even the bow seat, facing backwards) and paddle. Great, if the wind isn't blowing. But when it does, the paddler will experience leehelm. If you want to go downwind, great. But move amidships, the boat will be easier to control, and the paddler should be able to paddle any point relative to the wind. Want to go upwind, easily? Sitting just behind the center thwart, just turn around. Now the boat is trimmed bow heavy, and will only go upwind.

With this playing around, a canoeist may find the perfect sitting position- using the tendency to weatherhelm (turn upwind) while underway to balance the turning effect of the forward stroke- voila, no j-strokes needed!

The concept learned help one understand how any paddled boat behaves, or why it behaves badly, or can be made to behave.