A kayak stability question

I’m not trying to hijack the OP’s thread, but this is a somewhat similar question and concerns stability of an Eddyline boat, so I figured why not. If inappropriate, please let me know and I’ll start a new thread.

I just picked up an Eddyline Fathom this weekend. My first serious sea kayak. Been paddling a Pungo 120 for the past 3-4 years, and since I get out on Lake Erie frequently and would like to venture further out, I wanted something more capable. I’m 5’10", 180.

Before I start adding foam to create more contact with the boat, I want to make sure my seat’s in the right position fore/aft. It’s got 6 inches of adjustment available. Since I can position the seat anywhere over that six inch range AND adjust the foot braces to give me the right knee angle wherever the seat falls, how can I determine where the seat is supposed to be? I’ve been told that this can make a huge difference in stability in sea kayaks.

Well I don’t think moving the seat forwards or back will affect stability that much.

What it will do is affect the trim of the boat and change how it weathercocks. You need to try it out in some differing windy conditions to see how seat placement affects the kayak.

Moving the seat forward a little would also make paddling against oncoming waves somewhat easier.

The fore-and-aft position of the seat will have a major effect on the reaction of your kayak to the wind. To sort this out:

  1. Paddle into the wind. If the bow tends to be blown sideways and down wind and it is difficult to maintain course, then move the seat forward half an inch at a time until this behaviour ceases.
  2. Paddle with the wind on the quarter. If the kayak tends to round up into the wind, even with the skeg deployed, then move the seat half an inch aft at a time.
  3. Finally, let the kayak drift in the wind. Most well-balanced kayaks will end up across the wind. You can adjust the seat to correct this. Forward to turn into the wind, backwards to turn down-wind.
  4. Find the compromise position that balances the above three adjustments.

This is a simplified analysis of a complex subject, but it will be a start. Adjusting the seat correctly will aid dynamic stability by improving the reaction of the kayak to wind and waves.
Nick.

@David R said:
Since I can position the seat anywhere over that six inch range AND adjust the foot braces to give me the right knee angle wherever the seat falls, how can I determine where the seat is supposed to be? I’ve been told that this can make a huge difference in stability in sea kayaks.

From the EDY website: “The seat has 3 inches of fore and aft adjustment which allows the paddler to change position relative to the thigh pads for the best fit.”

Once I had my EDY seat set up in the most comfortable position which gave me good contact, I asked an instructor to check the trim. It was fine. Has nothing to do with the kayak’s stability. In windy conditions use the skeg if needed. Easier than readjusting the seat and foot pegs - although both can be easily done on the water (so long as it’s relatively flat).

Congratulations on your new boat. You might enjoy reading Ocean Paddler’s review: https://eddyline.com/wp-content/uploads/OP_Fathom_Review.pdf - if you haven’t aready.

Just a quick note from a newbie. I have a 10" Pelican Maxim kayak (http://www.canadiantire.ca/en/pdp/pelican-maxim-100x-kayak-10-ft-0798514p.html) which is a pretty basic rec. kayak. I am 5"6’ 160 lb give or take and as green a paddler as they come. I find this boat very stable and feel very comfortable (perhaps too comfortable even). The foot pegs have enough adjustment for longer legs so I am sure at 5’8" you will fit just fine. The weight limit is 125 kg.

Thanks, you guys. Sounds like exactly what I needed to know. Looking forward to getting this thing tuned in!

I should mention that following other discussions here I should not recommend or in any way endorse rec. style kayaks due to their flotation issues when swamped. Just wanted to mention that.

@SpaceSputnik said:
I should mention that following other discussions here I should not recommend or in any way endorse rec. style kayaks due to their flotation issues when swamped. Just wanted to mention that.

Perhaps not, but they’re about as stable as any boat can be. Used near shore in warm water for short distances they can still be a lot of fun. The problem with rec (wreck) boats is that people try to use them way beyond their “designed” purpose.

We have two rec kayaks so the kids can have fun with us. Very stable and it’s easy to swim from them. Fishing us simple too. They are fat and slow, tracking like a basketball but we knew that before getting them. Nothing could be farther from my elite surfski.

For a complete newbie figuring out what is this “designed” purpose can be a problem.

@SpaceSputnik said:
For a complete newbie figuring out what is this “designed” purpose can be a problem.

A good observation. This is completely the fault of the mass-production recreational kayak industry. Well, some of it is the naivety of people… but let’s just gloss that one over, shall we? :wink:

@SpaceSputnik I just did a quick google on “recreational versus touring kayaks”. I didn’t find the site I most wanted, looks like it no longer exists. But I did find a few that talked about suitable use for each type, like this -
https://www.rei.com/learn/expert-advice/kayak.html#TypesofKayaks

I completely agree it could be better, like talk about the reason for features such as perimeter lines. But trust me, you will figure that out in the first half hour of that rescue class. Also the reasons some prefer skegs over rudders. :slight_smile:

thanks Celia

@SpaceSputnik
Here’s a link which talks about the different types of kayaks. Also contains good info on skills, weather, cold water, etc. Created by four ACA certified Level 4 instructors:

http://www.paddlesafely.com/kayaks/

Okay, so I took the boat out and ran through nickcrowhurst’s well-written instructions. And apparently I’m a moron. I had a nice little headwind at times, so I felt pretty good about the test conditions. I’d started with the seat in the middle of the fore/aft travel, and the boat seemed to have a hard time tracking straight, so I kept moving the seat forward. And forward. And forward. It’s almost as far forward as it can go now. Each time I also adjusted the foot braces to get my legs back where they need to be. With the first adjustment, the directional stability seemed to get better, somewhat. That’s why I kept going. But honestly, once I got to where it is now and just paddled around for awhile, I couldn’t keep that boat going in a straight line to save my life.

I checked myself constantly to see if I was leaning the boat to one side or the other, and although this boat definitely wants to tilt (as mentioned by some people earlier in this thread), the moments when the front would suddenly track off course don’t seem to be connected to this. I’m at a loss as to what’s causing this…I have no problems going straight in my 12-ft recreational boat, which I’ve been paddling for 4 years. People who would know have complimented me on my stroke, so I don’t know that I’m doing something wrong with that. I’ll just be paddling along and…whoops. The nose veers off course. I was constantly having to edge and correct to get back on course last night. The only thing the skeg seems to do is make it that much harder to steer back ON course, from what I can see.

Any advice would be appreciated.

Move the seat back to, “With the first adjustment, the directional stability seemed to get better, somewhat.”

When the boat veered off course what was the wind and wave direction in relation to the boat.?

@David R said:
The only thing the skeg seems to do is make it that much harder to steer back ON course, from what I can see.

The skeg’s job is to force the kayak more downwind. It is not there to make the kayak keep its direction better in all wind directions.

If you felt the skeg working against you when you were trying to force the kayak upwind, the skeg behaved just as it should.

Also, it is not clear to me whether your kayak went more downwind or more upwind than you wanted. I understand from your comment that you were not paddling straight into the wind (“headwind at times”) but rather into’ish the wind. This is in line with nickrowhurst’s suggestions earlier in this thread. However, when you do that experiment, you can’t just focus on whether you are keeping your course or not. You have to consider if your kayak seeks into the wind or away from the wind when it deviates from your intended course. It is quite possible that you started with a seat position where the kayak would seek too much away from the wind, then found a seat position where it was generally neutral and then continued the adjustment in the same direction until the kayak would seek too much into the wind.

Am curious how far the skeg was deployed. Fully? Half? Quarter?

You know too that, like sailing, sometimes your heading is different than your course. Sometimes sneaking up on a point is easier than a direct straight course. You can fight waves and wind or you can “tack” and sneak up on the intended destination.

For example my Cheasapeake 17 loves to go into the wind and wave from dead on to a 45 degree. It too will go down wind real good with some surfing, depending upon load. So I can fight a beam on wind and wave or do a 45 degree off the wind until I get high on the destination then turn the boat to a down wind.

Wind and waves are not constant in velocity or size or direction. It is possible that at times your boat was hit with a combination of forces that turned the boat when other times it was stable on course. Every boat has a personality.

My first priority would be to position the seat where it would allow easy ingress and egress to the boat in the fashion I am used to. Then I would adjust the seat for trim as long as it didn’t interfere with ease of getting in and out of the boat. As for the boat not tracking, get used to using the skeg to some degree–even when going to windward if needed. There will be times when you will also need to edge and paddle shift and maybe even use less than a symmetric stroke. All of that will be automatic in time.