Balance and seat placement

Reading kocho’s thread on his new Z155, he mentions how moving the seat effected his boat’s behavior to wind. Flatpick explained this as the the factory seat placement being a neutral position relative to balance, and how movement one way or the other can effect that.

So here’s my question … actually 2 questions.

First, if the balance of the boat shifts to toward the stern, how will it behave in wind? How about if the balance shifts toward the bow? Will all boats have the same behavior?

Second question: assuming the boat is balanced, and you add 10 pounds of gear in one sea bag, would you put that bag in the aft or bow compartment?

I recently lowered my seat, and noticed that there are bolt slots for moving the seat forward or backward. Fit wise I don’t need to move the seat. I was wondering however if I noticed a tendency to weather or lee cock, should I consider adjusting balance by moving the seat?

boat trim

– Last Updated: Nov-01-10 8:41 PM EST –

When you weight the front of a kayak, the bow sits deeper, and has more bite in the water. Therefore the stern blows downwind faster than the bow, and the boat tends to point into the wind (weather-cock).

When you weight the back of a kayak, the stern sits deeper, and has more bite in the water. Therefore the bow blows downwind faster than the stern, and the boat tends to point downwind (lee-cock).

Changing your seating position may or may not produce a perceptible change in how the boat trims in the wind. I think what Steve was saying (comparing the Z to the Tempest) is that a more rockered boat will be more sensitive to where the center of mass is in the boat, which makes sense.

When loading a boat with gear, it's best to keep the gear close to the center of the boat, and you generally want to keep the boat trimmed evenly, which means putting perhaps 40% of your weight in the bow hatch, and ~60% in the day/stern hatches. (Not equal bow and stern, usually, because the bow compartment is further from the center of the boat than the stern compartments.)

If I had a single 10 pound bag of gear for a day paddle, I'd put it in my day hatch right behind me.

When loading your boat consider the wind conditions you expect, and where you're paddling. If you plan to paddle downwind all day, I'll consider putting a touch more weight in the stern, so the boat tends to point downwind a bit more easily. If safe shore is going to be to windward, I might put a touch more weight in the bow, to ensure that I'll be able to paddle back to windward if things turn bad. I'd just use minor trim adjustments in this way though. Nothing dramatic - you certainly want to be able to turn the boat through all points of the wind however you have it loaded.

It is nice to have the boat as trim
as possible, but if it is out of trim, I would rather be a tad bow light then bow heavy.

I am not thinking of the wind here, but just for paddling.

If you are bow heavy, you are going to be zigging and zagging as the bow plows, and you will be constantly doing corrections.

On the adding weight: If I am carrying a lot of stuff, I will try to get it equally distributed between the front and rear compartments.

On a day trip, a pound or two out of trim on a long boat won’t make much difference.

Jack L

Trim and weather helm
As Nate summed up, a bow heavy boat will tend to weathercock. Moving the trim towards the stern will reduce the amount of weathercocking, and on some boats may even induce leecocking.

This general behavior is common to all boats, but the degree to which changes in trim make a difference in weather helm is specific to each design.

If you are happy with the trim of you boat empty, and are going to add 10 pounds of gear, add it to the rear compartment right up against the bulkhead. This will produce the least change on the boat’s trim.

If you want to reduce weathercock, load your gear in the back of the back compartment, or if you want to increase weathercock load the front.

You’ll have to play with your boat in a variety of conditions to get a feel for things.

all good stuff
the above posts sum it up nicely. yes a heavily rockered boat will have a more sensitive nature to trim BUT all boats will be affected. It literally moves the pivot point of the vessel by shifting the load.


Good description
Nate, your description is very readable and concise, well done.

Thanks Nate …
… Explains it very well. Going to leave the seat where it is, and move the ditch bag up from the rear to the day hatch.

Since putting 10 pounds …
… in the rear compartment, the boat seemed to hold course a tad better. But that was only one trip … couldn’t decide if it was in my head, or that the stern was sitting just a bit lower.

Good suggestion …
… Will move the bag up to the day hatch. Thanks.

Yep, the boat has a good amount …
… of rocker, which is why your comment on the Z and T caught my attention as they are well rockered boats too.

Besides me, all carry is a ditch bag, so I should be able to figure the best balance for that. Would be more to think about if I was carrying varying loads.