Your #1 source for kayaking and canoeing information.               FREE Newsletter!
my Profile
 





Family kayak vacations this summer
San Juan Islands
See Whales & Eagles
www.crystalseas.com/InnToInn
 
Advice, Suggestions and General Help New Topic Printer Friendly Version

  Initial Stability in a Sea Kayak
  Posted by: aocpaddle on Nov-14-13 10:54 PM (EST)
   Category: unassigned 

Why would I not want to purchase a kayak with the highest initial stability - and secondary stability for that matter - assuming same width/length?

 Great Products from the Buyers' Guide:

Touring Kayak Paddles

Full Size Sail Rig

Sport Cases (Electronics)

Dry Tops

Emergency Cases

Table of Contents




Messages in this Topic

 

  Some basic stuff
  Posted by: Guideboatguy on Nov-14-13 11:29 PM (EST)
-- Last Updated: Nov-14-13 11:56 PM EST --

Here are three reasons.

1. Any boat this is highly stable is resistant to tipping. "Duh", right? Read on. Any boat that is resistant to tipping tends to stay aligned with the water's surface, which is great when the water is perfectly flat, but not when the surface of the water tips a whole lot, as on the edges of sizable waves. A very stable boat constantly "tries" so stay aligned with the tilting of the waves, so you get tossed back and forth violently in the process, to the extent that you might find your "stable" boat on the verge of tipping over an awful lot of the time because your center of gravity gets so catywumpus. A boat that "tips easily" rides much more smoothly in steep waves, because in tipping easily, it more easily remains upright as the water's surface tips beneath it.


2. A stable boat is a slow boat. One way to make a boat faster is to reduce the amount of wetted surface area that there is in proportion to water displaced. Take this to the extreme, and the part of the hull that's in the water, as viewed from one end, looks like half a circle. That hull shape has no stability at all, and you don't want that in a boat (though some specialized racing boat are pretty close to that shape). The boat at the opposite design extreme, the one with the most wetted surface area relative to water displaced, has a very flat bottom. Yes, that's stable, but all that unnecessary surface area causes extra friction as the boat moves through the water. Somewhere between those two extremes is a hull shape which moves through the water much easier than a flat-bottomed boat, but is a lot less tippy than a round-bottomed boat, and often includes the good secondary stability as described in #3 below. In fact, this is a perfect illustration of why no single hull design does everything, or even many things, well.

3. Others here will be more expert than I, but the geometry of the situation makes me think you can't have high initial stability AND high secondary stability in the same boat. Here's why. A flat-bottomed boat when tipped to the extreme ends up with one edge shoved deeper into the water and the other edge lifted right out of the water. The result is an effectively narrower hull (there is less hull width in the water after the boat is tipped than there is when it sits flat). Naturally, a boat that "gets narrower" as it leans to one side also becomes less stable. A boat with high secondary stability does the opposite. The width of the hull that is in the water actually becomes greater when the boat is tipped, so the farther you tip it, the more "tipping effort" is required to tip it even farther. So, going back to my first statement, I can't imagine a way to combine these two opposing geometrical features in a single hull.

Other Stuff:
All these basic ideas interact with each other. As one example, moderate to extreme leaning of the boat can be very handy for several reasons, including to aid maneuvering, or to keep from getting flipped when suddenly entering water with a substantially different cross-wise speed relative that which you've been paddling in so for (this happens in swift water when when entering an eddy or leaving an eddy), and especially since many boats that tip easily also "firm up" (with increased stability) when leaned, it will be a lot easier to take advantage of leaning the hull. Leaning a highly stable boat isn't nearly as easy to do, especially since, as pointed out above, it actually becomes a lot more precarious a perch for the paddler when this is done. I'm sure plenty of other examples could be made along such lines.

Oh! OH! All that I've said applies to hulls in general, but since I'm not a kayaker I didn't think of one really obvious thing. A boat that's super stable (wide, flat-bottomed) is hard to roll, and the ability to roll is what makes a kayak so incredibly "safe" for a skilled paddler when simply making your way to a nearby shore isn't an option. A skinny boat "tips easily", but is likely to be more stable when leaned AND can readily be rolled, so tipping over isn't anything to worry about anyway (and though off the subject, it's worth mentioning that learning to roll makes you a lot less likely to tip over in the first place because of the feel for "rotation control" that you acquire).

 
 
  Try a Reflection...
  Posted by: t.george on Nov-15-13 9:30 AM (EST)
There are other ways of creating stability, there are always trade-offs. Sterlings Kayaks "Reflection" has very good initial stability and an extreme amount of very progresive and deep secondary stability yet also is one of the easiest rolling boats around. I believe much of this is accomplished through the rocker profile changing the "in water" volume as the boat is heeled over. I weigh about 155# and often put even smaller first timers in the Reflection and none have had any trouble edging the boat, I also know many in the 250# range that have the same experience in it. The Reflection is in fact almost too stable and prdictable in all conditions; such that if you don't somewhat regularly paddle other boats your skills get a bit lazy. There is a trade-off for speed; while the Reflection has a decent cruising speed it won't go much faster no matter the effort. No other sea kayak surfs like it though :>). All the best, tOM
 
 
  Good example of what I meant
  Posted by: Guideboatguy on Nov-15-13 11:07 AM (EST)
You say it is easy to edge, which of course could not be true if it were extremely wide and flat-bottomed. It's an example of what you can do with a hull that falls between the two extremes I mentioned.
 
 
  Thanks for the Replies!
  Posted by: aocpaddle on Nov-15-13 6:55 PM (EST)
Thanks for all the wisdom in your responses (and for not assuming I was a troll).

I guess my original questions was borne out of a little frustration from my most recent open water paddle. I have experience paddling a couple less stable hulls (initial stability I guess) which I particularly enjoy for their speed and acceleration: an Epic 18X&V8 and a Current Designs Cypress. Both are soft chined and a little lower in initial stability. I am fine on flat water or heading into wind chop, but give me any more that 1 ft. wind chop on the beam and the wobbly feeling just messes with my mind. Bigger swell or wind waves and I really can't avoid tensing up and feeling nervous/anxious.

In contrast, I have paddled an NDK Romany and Seda Ikkuma in the same or bigger conditions and I can just relax and let the boat do its job. I feel more in control, more comfortable bracing, etc. On a side note, I find both these boats easier for me to roll so that also helps calm nerves I guess. With these boats I feel like a much better kayaker.

Not sure if I just need psychotherapy, hypnosis, or what? Or should I just stick with stability and give up the speed aspect.
 
 
  You're Not Alone
  Posted by: Kudzu on Nov-16-13 4:50 AM (EST)
A kayak buddy of mine has had a QCC 700 for years and he prefers to borrow one of my boats with a bit more initial stability.
 
 
  Spend more time mixing it up with boats
  Posted by: Celia on Nov-16-13 10:16 AM (EST)
-- Last Updated: Nov-17-13 11:00 AM EST --

The NDK Romany is one of those boats that many people keep around because there are many times in your paddling where you want to be in a boat that you can forget about. We have two boats in the fleet (one is a Romany) that we keep because there are times where we want to paddle but want a boat that will do a little babysitting.

This is not something to be looked down on, especially as you get older. Getting on the water at all is more important than the macho factor of the paddle.

That said, if you don't learn to relax more you are preserving an unneeded risk in your own paddling. One and two foot chop is not the kind of thing that should alarm anyone who wants to do open water paddling. And tensing up will inevitably make you a swimmer at some point.

I suggest that you spend time with boats that challenge you a bit on initial stability and find a way to relax more. Perhaps you could focus on sculling, not rolling, so you are down and in the water but still not swimming. A roll is so fast, it might not be helping you much with your tension.

Can you find pool sessions over the winter, so that you can come out in spring with some headway on this?

 
 
  Good Advice
  Posted by: aocpaddle on Nov-17-13 9:33 PM (EST)
Thanks for the advice. I have spent a little time at the pool, mostly practicing rolling. I will emphasize sculling next time I go to the pool and will continue to try to get more comfortable/relaxed with other stability profiles. It can only help me become a better paddler, I suppose. Maybe I just will continue to need my Romany babysitter. Which leads me back to my original post, besides the speed/acceleration, what is the joy of paddling a lower initial stability kayak? What are the other advantages over a kayak like a Romany, or similar hull design?
 
 
  Other boats
  Posted by: Celia on Nov-18-13 10:13 PM (EST)
There are not a lot of boats out there with the combination of secure feeling and responsiveness of the Romany. Once in a while someone just gets it right.

But speed or a spritely quality - as in acceleration - can make a boat more pleasurable to paddle. I stay with my Vela for that reason, even though there are some weaknesses as a rescue platform compared to the Romany. While both have similar top hull speeds, the Romany is a pig at acceleration compared to the Vela. But the Vela will ask more of the paddler in terms of staying relaxed when things get dicey. It's the trade-off.
 
 
  Predictable Resistance
  Posted by: willi_h2o on Nov-15-13 12:53 AM (EST)
-- Last Updated: Nov-15-13 1:05 AM EST --

No one likes surprises, uh-oh moments, etc., etc.
A "rounded" bottom kayak will give the paddler a very
predictable feel when among the waves.
A big ol' flat bottom feels safe; until that exact moment
where expletives are uttered and you get dumped.

How a kayak "resists" movement is often described
as its primary/secondary stability.
Various shapes of the kayak hull can modify,
the amount of resistance, to the outside forces.

http://youtu.be/ND_hMPtYkIY

I would say initial stability is that secure feeling
you have upon first entering the kayak.
Secondary stability is that feeling for when
you're about to be dumped , whether it is a
violent capsize or a just a gentle sliding roll over.

It's always a highly individualized unique purchase.
The kayak you buy, needs to fit your criteria; not someone else's.

Love the quote below :
"What the rest of the world paddles is
only important to the rest of the world."

 
 
  OK, but note that most of the ww kayak
  Posted by: ezwater on Nov-15-13 6:15 PM (EST)
community have gone over to flat-bottomed, sharp chined kayaks. Even creekers are trying to do it, though they try to find flattish creek boats where the edges are lifted enough not to catch rocks.

In whitewater, flat bottoms and sharpish chines are necessary for optimum control. Except for steep creeks, round bottomed kayaks like the old Dancer are invariably pigs.
 
 
  Is this a sponsoon troll?
  Posted by: seadart on Nov-15-13 1:13 AM (EST)
 
 
  Probably not
  Posted by: bartc on Nov-15-13 8:11 AM (EST)
I get the physics.
But like many trying to move from beginner to intermediate, I still like initial stability (for photos and just general comfort), while wanting that secondary stability in reserve for rougher water. Finding the right compromise, as you probably know, is idiosyncratic.
But the question makes sense to most beginners.
Is this guy a troll? Have no way of knowing.
Please don't assume the worst, though.
What's interesting is that there are boats out there that have been rated by those companies that rent to all levels of paddlers that can have a nice compromise - at least by their ratings. I'm looking for and at a couple of those myself.
 
 
  Another analogy
  Posted by: Jaybabina on Nov-15-13 8:04 AM (EST)
It's like riding a three wheel bike vs. a two wheel bike.
 
 
  ok, that was really good
  Posted by: slushpaddler on Nov-17-13 10:31 AM (EST)
I was just trying to think of a succinct and accurate answer. Yours is perfect.
 
 
  What do you want to do with the kayak?
  Posted by: Celia on Nov-15-13 9:15 AM (EST)
-- Last Updated: Nov-15-13 9:16 AM EST --

Shooting photographs often means that it is better to sacrifice some secondary stability (such as it may exist - there are arguments about that). It makes shooting photos easier and face it - very few people are going to be taking close-ups of pelagic birds in a sudden squall and steep breaking 4 plus foot waves. At that point the hands will be on the paddle, not a camera.

But high initial stability can get in the way for more playful purposes, because it could increase the effort needed to get the boat onto its full edge. Rock gardening is one example.

There really is no answer to your question without considering the intended paddling environment.

 
 
  You may be unstable yourself. So
  Posted by: ezwater on Nov-15-13 10:24 AM (EST)
go ahead, and buy the most stable kayak you can find. Or, find a used Hobie catamaran and take the mast off.

When you find that the other sea kayaks are leaving you in the "dust", or are running rings around you, then find a sea kayak that performs.
 
 
  I believe you will find
  Posted by: rjd9999 on Nov-15-13 11:06 AM (EST)
that the performace of a highly stable boat will be something you will outgrow quickly. Characteristics (wide hull, deep keel, etc.) which make a boat highly stable tend to make the boat slow - both in forward progress and in response to conditions.

A sheet of plywood has excellent initial stability, but as a paddling platform, it is the worst possible design. If you were to try to stand on it, it would tend to behave according to the pressure (and location) of your weight, it's inherent degree of bouyancy, and whatever movement the water would provide. Even though it has high stabiliy, once you put weight on it, those characteristics change instantly and it will try to escape from the counter forces of your mass and it's bouyancy and will become catastrophically unstable (it will attempt to move to the sides or flip at very slight provocation).

While this is an extreme (and unrealistic) scenario, stable boats also share some of these problems. They tend to wallow in the water and when the forces exceed the design, they tend to capsize VERY quickly and be slow to respond to paddling imput. What looks and feels stable initially may be extremely unstable when you add weight (such as for a trip) and the conditions change.

A kayak needs to behave more or less predictably, allowing the paddler to adjust and respond. Often, some of the less stable designs perform amazingly well when conditions become rougher and/or weight is added to the hull.

There was a documentary (it may have been a NOVA episode, but I can't seem to find it at the moment) where a paddler who could barely keep a baidarka (with a bifurcated bow) upright when stationary. He rolled up a couple of times after launching due to the lack of initial stability. Once the the boat was on the water, the performance in swell and surf far exceeded expectations. The boat become more stable and responsive at speed and is probably a good example of the other extreme (ie. plyboard sheet).

Most of us don't want a boat that tippy, but all of us probably want a boat that fast and responsive. Every hull in between the two states must be a compromise or there would be a need for a single hull design and everyone would use it.

Rick
 
 
  I believe you will find that replying to
  Posted by: ezwater on Nov-15-13 11:37 AM (EST)
the original poster often requires scrolling up to the top of the thread so as to click on the very first "reply" button.

If you click on the "reply" button at the bottom of the thread, you may seem to be replying to some crabby person who has just posted something quite unrelated to your thoughts.

Just sayin'.
 
 
  stability
  Posted by: ppine on Nov-15-13 12:52 PM (EST)
Some good post here. With experience, most paddlers gladly give up some initial stability for really good secondary stability. That trade-off allows for greater speed and safety in rougher water. Some paddlers need to practice bracing to get their technique to the next level. Then the more advanced boats make more sense.
 
 
  that was great
  Posted by: slushpaddler on Nov-17-13 10:30 AM (EST)
Nice thumb in the eye of the volunteer forum cop.
 
 
  A lot, real lot, of people like . . .
  Posted by: Glenn_MacGrady on Nov-16-13 7:28 PM (EST)
. . . stable boats. Thus the popularity of rec kayaks among newbies and intermediate kayakers and tandem canoes for solo wilderness tripping.

Many posters here are not within those groups, and have a preference for faster or higher performance boats.

Much of paddling is mental. It should be fun. Or at least peaceful. No one has fun or is at peace when constantly worried about a twitchy boat.

Stability is also a value when you want the craft to serve as a platform for some activity other than the act of paddling for the sake of paddling -- such as fishing, hunting, photography or cuddling.

If you "outgrow" a stable hull, you can simply get rid of it for a tippier one. Cuddling in a boat doesn't require marrying it for life.

I paddle tippy canoes, but that puts me in multiple minorities. I decided to be more majoritarian in this response.
 
 
  True
  Posted by: rjd9999 on Nov-18-13 12:51 PM (EST)
not everyone wants to have a boat that challenges their skills, but not everyone wants to paddle a water plow, either :).

There are times (fishing, for example) where I attach what is essentially an outrigger to my boat (paddle attached behind the cockpit with a float on each blade) and that handles whatever stability I need. Paddling a barge is frustrating and leaves a brown stain on my seat.

I think most folks who paddle a barge amongst a lot of faster boats learn to hate them, too :).

Rick

 
 
  If you want help with that brown stain,
  Posted by: Bob_d on Nov-18-13 3:26 PM (EST)
you will have to start a new thread.
 
 
  practice in breaking waves
  Posted by: capefear on Nov-18-13 4:37 PM (EST)
-- Last Updated: Nov-18-13 4:41 PM EST --

"give me any more that 1 ft. wind chop on the beam and the wobbly feeling just messes with my mind. Bigger swell or wind waves and I really can't avoid tensing up and feeling nervous/anxious."

"I can just relax and let the boat do its job."

Practice in breaking waves will bring you to a new level like nothing else. I think it's because in breaking waves, once they reach a certain level, your kayak's stability can no longer protect you. You need to have a different skill set in place.

I was out yesterday in my P&H Bahia playing in 3-4' surf. The Bahiya was largely considered quite unstable, on this board included. I got thrown around a little, spun around a little, had to roll up a few times. None of this had anything to do with stability. I own several kayaks. In those moments, a kayak's stability gets pretty well lost for me. It's more about leaning into waves, blade angle control, adjusting to unexpected movement, controlling movements where you can, relaxing your left leg to bring the kayak back to level up from the right, relaxing your right leg to bring the kayak back to level up from the left, etc. Edging doesn't work well beyond a certain size and wave-break intensity. The wave will knock your body right over unless you're laying your body over into it as it hits you. That's why I say "leaning into waves" vs "edging into waves". With less impact, edging works fine.
In any case, once you iron out controlling your balance and ability to right yourself with forces acting on both your body and your boat, the twitchiness goes away. That then leaves other things to appreciate or not appreciate.

In some ways, if you're planning on taking on bigger water, I think you're better off working your way through that nervousness at a less rough level. It doesn't take that big of conditions, and no matter what boat you're in, once you tense up and feel nervous/anxious, the boat will no longer keep you upright.

I find this an interesting thing as far as the psychological factor. If a group paddles out of a deep channel inlet into 4' short-period open water, there is usually a little anxiety about the open water conditions for a while. If a group launches into that same water through breaking waves, everyone is breathing a sigh of relief and is relaxed in the same open water conditions. I'm no different. If I can bust through an intimidating surf launch, I'm immediately relaxed in the open water. A whitecap on the crest of a steep wave no longer seems intimidating. It seems playful.
So start by taking that Cypress out to some 2' breaking waves. Learn what knocks you over. Learn how to counteract that. Learn to reliably and automatically sit up from a deep brace. Learn blade angle control, so that you can sweep forward or backwards with either hand with either a high or low brace to keep your body on the surface. It will give you that little bit of extra support while you sit up if necessary.
Diving blades due to a diving blade angle, and two tense legs up in both thigh braces, are usually the things that prevent a person from sitting back up after a side-surf, for example.
As a simple safety precaution, I would advise people against flirting with white-capped open water conditions without developing this as a prerequisite skill set. Since you're talking about building conditions, and the possibility of a more stable boat being a better solution, I'm suggesting developing a skill set that will protect you better than a more stable boat. Some may suggest doing both. But I recommend picking up the skills that go beyond your kayak's stability, and then re-evaluating the performance of your kayaks.
Use the pool to learn to roll, blade angle control, recovery from a deep brace if you want. Once you have that, you could play in the pool for years, and probably not pick up the open-water capabilities that you would in a few visits to breaking waves with the ability to knock you over and side-surf you for a bit. If you don't have a roll, the entire activity is largely useless, as there is little difference in the mechanics of sitting up from a deep brace and a roll. But you seem interested in what it takes to push things further more than just wanting a more stable boat for what you already do. And a person usually picks efficient kayaks because that is something that turned them on about kayaking. I guess you said exactly that: "I particularly enjoy for their speed and acceleration: an Epic 18X&V8 and a Current Designs Cypress" So I'd definitely push skills over new equipment. I'd love to have a Cypress and an 18X.

 
 
  More Great Inspiration
  Posted by: aocpaddle on Nov-18-13 8:35 PM (EST)
I found your post particularly inspiring. I'm going to bring the Cypress to the pool this week! I also have a nice place to bring it into some small (1 - 3 ft) breaking surf as well. This makes me think of the nice step forward I took once I became confident side surfing, rolling, and playing in the surf with my Romany. My only trepidation is I am not 100% consistent rolling the Cypress - but will work on this in the pool as well. FWIW: The 18X and V8 were both demoed/rented boats that I spent time in and liked for their acceleration but felt more similar to the Cypress in terms of stability.
 
 
  too true
  Posted by: rjd9999 on Nov-19-13 4:20 PM (EST)
that the overall stability of a boat is largely a function of paddler skill, not hull design. The reason is obvious: any moderate sea/swell/wind condition quickly surpasses the envelope the hull design can handle. Odds are that the conditions will exceed the design when one enters or exits the surf zone as well (that is, in a sea kayak). WW kayaks and canoes surely cannot handle severe conditions on their own, it takes a paddler that is confident and capable in the prevailing conditions.

It is the paddler that provides the overall capability of the boat. A paddler who isn't comfortable in the boat will have a much more difficult time in developing the necessary skills. Those who opt for a truly stable boat will usually lag behind both the performance and learning curves.

Rick
 

Google
 
Web Paddling.net


Follow us on:
Free Newsletter | About Us | Site Map | Advertising Info | Contact Us

Sweepstakes

©2014 Paddling.net Inc.