A kayak stability question

I spent many hours in my elite surfski paddling with my feet in the water because it tipped over so easily. And I’ve been an avid kayaker for 40 year with very thin kayaks. My point is, practice, practice, practice. You’ll get it over time.

Thanks for the great responses! I’ve been reading a lot of what goes into a Kayak. Length, width, chines, cockpit size. Etc.

Celia brought up an interesting point about my weight range being at the top range of this particular boat. At first I scratched my head because I thought I fell into the “medium” category at my height and weight. But it now makes sense because my Wife who is same height but 30lbs lighter than me zipped around and pretty much owned it. So I’m guessing she would fall into the small category.

Anyway, That’s why I asked the basic question, if this same boat was another couple of feet longer, would it behave differently.

William

@wrz0170 s,… When I got into it, she was twitchy from the get go…

When you learned to ride a bicycle without training wheels was it wobbly or rock solid the first time?

At 24" beam it was likely you.

@Guideboatguy I apologize for a too-quick response on one point, and agree that is was wrong. I was focused, probably overly, on the chance that as a new paddler the OPer could go out and try a longer boat without confirming its intended paddler. A really big guy would not be able to physically get into a sea kayak that was made for a smaller paddler with maybe subtle seeming diffs from the full size version. A medium sized person could, in fact I know a lot of more experienced sea kayakers who keep such a boat around for its increased playfulness in the right circumstances.

Anyway, point made and maybe the OPer will start looking for a little more boat. Again, did not mean to diss you.

Interesting thread. The Rio is labeled a recreational kayak by Eddyline. It’s hard chined as is the Eddyline Equinox that William (the OP) said he purchased and found very stable in his first thread.

I can’t agree that EDY boats don’t sit flat in the water if the paddler’s weight is balanced in the cockpit. I used a small bubble level on my Samba last summer. It was level horizontally while I was sitting relaxed and centered. While moving forward that changes, as it should if you’re rotating.

I’ve demoed kayaks with rounded chines and prefer the communication of a hard chine. Most likely because that’s what I started and stayed with.

Celia’s mention of size and weight of the paddler made me think of a person’s center of gravity. Am currently paddling a 21" hard chined kayak. A friend who is taller and heavier (he’s very fit and a much better paddler) has the same kayak and finds it twitchy in waves and chop. I think it’s the most stable and secure kayak I’ve ever paddled in 2.5’ foot waves and confused water and attribute our differences to my lower center of gravity.

Rookie, it is also volume. One thing that the canoe folks do very well and gets disregarded when it comes to kayaks is how much weight is required to sink the canoe to its optimal waterline. Sink it too little it bobs around and you are not going to get the most out of the control surfaces on the hull, but it won’t be unstable in the way we think about it with kayaks. Sink it too much and it starts getting unstable. It works the same for kayaks, but you don’t see the clear numbers telling you where that waterline is with kayaks compared to canoes. It is more easily discovered by the kayak’s behavior and, in some boats, whether the bow and/or stern are properly engaged with the water.

That is where weight comes in - though someone sticking higher out of the cockpit does have more work to do to maintain their center of gravity. You are likely a bit below its highest design weight so are unlikely to go past that magic point. Your friend may be right at it so any boat movement puts him deep enough to start altering the stability.

I can’t comment about the specific boat, since I’ve not paddled one.

Fit could be a problem, as well. If the paddler is not in good contact with the boat, it will not feel stable.

Length affects stability some. Since the boat, when it leans, is spinning around an axis point somewhere above the waterline that varies with the total center-of-gravity of the boat+paddler. Beam, and as this is a medium to wide 24 inch beam, certainly affects the feeling of stability more. I expect that the length was less an issue for this paddler that some other factor in the boat/paddler configuration. Length does (often) add to the LAW (length at waterline) and this may affect the center of gravity (a wide boat will tend to gain less LAW than a skinny one and the paddler might need to have this hull deeper in the water to feel comfortable). Adding weight to the boat can increase LAW and it is possible that the trim/fit for this paddler was altered enough that the boat became (or felt) unstable. It may, or may not, have changed the stability characteristics of the boat, but there is no way to know this without testing the hull.

It is possibly true that the paddler’s center of gravity was wrong for the boat. Lowering the seat might have a major impact on this, but that can cause problems with paddling if one has to sit too deeply in the boat.

Guillemot kayaks has a decent treatise on stability and it is worth looking at the following link:

http://tinyurl.com/yckstbfc

Rick

And to add, we wear a sea kayak, we don’t sit in one. If you are lose inside it will feel unstable. If locking yourself in is uncomfortable them pad the inside of the deck so your knee area is lightly pressed inside. Make sure your foot pegs are in the correct position to create a snug fit.

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: