Stability in shallow arch bottom canoe

-- Last Updated: May-16-16 4:17 PM EST --

I own a Penobscot 174RX.

Edit may 16.: Correct is Penobscot 17RX

It is amazing to read reviews and see how different people experience stability. Some said there is no secondary stability at all. It flips over in a second.

Other find the secondary stability very good, and never been close to a flip over.

Checking other manufacturer`s canoes (with shallow arch) reviews, I was not surprised to find the same tendency in different views on stability.

Guess there is an exact limit on center of gravity above waterline for this type of hull. Above- and the secondary stability kicks in too late.

I really want the manufactures data on this. Now I just can speculate:

1. Is the design not changed since the days people was generally lighter?
2. Was it calculated with heavier hull back in the old days? (lower C/G).

Watching people do "planking", you can see the human`s body C/G is at the navel. Does it make sense to use the navel height above water line as a main factor in stability?

Now to those paddlers who flipped around in a shallow arch canoe:

1. Did they sit on a cushion that increased body height?
2. Wearing heavy gear or clothing on upper body?
3. "Amateur" paddling. Uneven paddling and switching sides all the time?
4. If a light kid or woman sits in front, and a heavy man sits rear, does the canoe roll along the side and not centerline? Negating the secondary stability.

Final word:
My Penobscot 174 does live, but never experienced tipping. I do feel the secondary stability, but not sure how close it is to continue rolling past this point.

What worries me, if some day we have to paddle on the same side a couple of strokes in heavy wind. What will happen then...

Today I started to lower the seats. The Old Town add on seats (backrest) build 5 cm (2") in height. I am now lowering the seat by total 7 cm. This will give me a net drop of seat height by 5 cm (2")

I do love my canoe, but I really want to know why some people tips it over. And those who find it really stable, what do they do right?

Comments welcome!

Can’t answer all your questions, but
for me it simply amounts to experience.

The longer and more you paddle, the better you get at it, and pretty soon hardly any canoes at all seem tippy.

For what it is worth, we have a Penobscot along with a bunch of canoes and that never has felt the list bit tippy

Jack L

The main factor

– Last Updated: May-12-16 7:22 PM EST –

is keeping your head and upper body centered in the boat. You can J-lean quite far without flipping. Lean with your head and upper body out over the gunwales, and over you will go. I don't think it matters what type of boat you are in, whether you are sitting or kneeling, or what your partner weighs. I do agree with Jack - experienced paddlers with a brace and a J-lean will stay upright and feel more stable. Inexperienced paddlers won't. I think it is as simple as that.

Side shape matters
Canoes with width down low usually don’t have as much secondary stability than those whose wide point is near the sheer

Canoes with significant tumble home can be “tippier”

Shallow arch is a generic term. You can also have shallow arch with too abrupt a turn at the bilge. And over you go if you heel it

I’ve owned some 30 canoes tested dozens more and in each test I try to find out where its tipping point is. So I have had a few baths

Some boats don’t tip like my WildFire but gently fill. My Dandy was the best at that

However I suspect that the Diisco is mainly paddled by people who have no idea what they are doing (not you. It’s a favorite livery boat)

These folk have no idea of the importance of keeping your head in the boundaries of the gunwales.

The magic spell is:

Keep your head on the centreline - and the secondary stability will do the rest.


I’d say so …
Swims are a little like plane crashes - you always look at the equipment, but they are usually they are caused by pilot error. I can go back through my pictures and find plenty of examples of swims caused by my paddling technique:

The bell buoy lean

The air brace

The J-Lean that didn’t quite do it

It happens - especially when you are pushing yourself.

To your point, there are things you can do to increase your stability in the boat. I find I am more stable kneeling than sitting. If you are going to sit, a lower seat generally feels more stable. A flat bottom boat will feel more stable initially, but will go over quicker once it starts (less secondary stability). Your shallow V hull might fell more tippy initially, but has more secondary stability, and might give you an extra fraction of a second to throw a brace. All good things to know, but I’d say that the 80/20 rule still applies - 80% paddler, 20% equipment.

Story so far…

– Last Updated: May-14-16 12:28 PM EST –

As a teenager in the sixties, I owned flat bottom wide canoe approx. 14`long. My friend and I had frequent long trips in a Norwegian fjord. I did a lot of solo paddling. Could paddle for 12 hours through the night.

Crazy days, no PFD, turning back was a shame. Never scared, even in high waves, but should have been scared. Only safety we got was extra paddle. I broke one, and had to paddle with half paddle rest of the trip. Learn the hard way.

Learning to paddle correct the hard way. Started to kneel in strong head wind due to less air resistance. But we preferred to sit.

We loved the canoe, but always talked about a longer and fast one. Reading books, we start to dream about nothing less than 17`.

Brought it with me (or more correct paddle it for 4 days) when doing service in the Air force. A large lake near airport, was nice, but the canoe was very wet due to short choppy waves.

Getting married and sold it. (owned it for 15 years) Close to a wreck with gelcoat worn off, and frost breaking up the moist fibreglass.

Bought a new one a few years later, not happy with it, and sold it.

Occasionally I rented or loaned canoes. Short terrible ones with a lot of rocker. No tracking, and dead in water after each stroke.

Two years ago the itch getting seriously worse. Starting to read and search. Getting fat, weak and lazy, I really needed a long canoe to get the speed I wanted with my old worn out "motor". The problem was I had to abandon the idea of solo paddling with a 17`.

Stupid, but I had promised myself nothing less than 17` 40 years ago. Buying a 15` and not happy, I would never forgive myself.

The quest for speed. There was only one option in Norway - Penobscot 17. I called the Dealer. Nothing in store. The Old Towns are hardly off the truck, before they are sold. But they expected a green Penobscot 17 next month. Listen -that one is mine!

Next month and one hour flight to the Dealer, and there was a red one outside the shop. Love at first sight! Pulling out the credit card and run inside. Sorry man, but we got a Royalex, much more expensive. Ouch that one hurt, but lighter and better, with even better second hand value. With no doubt I handed over the credit card.

My friends and I love the Penobscot 17`. Old worn out guys have the speed close to kayaks (those lazy Sunday paddlers that is). A bit of overkill with a large canoe designed for long trips, and not a short Sunday or weekend trip. But it is all about speed without sweat and high pulse, and still be able to carry camping gear with no worry of space or weight.

Tis is the third season with it. Finished to today with lowering the seats. Next I will glue in some blocks of hard foam to brace feet on. The canoe is extremely slippery inside, and feet feels like dancing around.

No doubt this will make the canoe even more enjoyable!

Thanks for tips guys!

As everyone else has said
As everyone else has said precieved stability is all about the paddler, (or at least 80%) and only slightly about the boat. Olympic K1 paddlers seem relaxed in a boat that I would immediately flip over, and I consider myself to have decent stability in boats down to around 19 or 20" width.

To reiterate the previous good points made, its all about learning to keep loose hips and lean the boat with your waist, not your shoulders. ALso, learning where your boats “point of final stability” is (meaning, the point at which you will actually flip) often its farther than people think.

Last, you can save yourself if you have a good brace in 90% of situations. It has to be fast, instinctual, and strong, but if you have a good brace you can bring the boat back from well beyond its tipping point. I can have water coming over the gunwales in a 27" wide racing canoe and save it 80+% of the time (certainly not 100% though).

So a shallow arch may seem tender, but its probably my favorite hull shape. One thing to note though is where the tumblehome is makes a big difference in final stability. Wenonah canoes have the bulge down low; the benefit is easier reach to the water, but the tradeoff is less final stability.

Compare that to a Bell / Northstar canoe that has the bulge up much higher, close to the gunwales; to me, these boats are nearly impossible to swamp because you keep gaining stability all the way until you flip, and the amount of stability gained as you lean is significant.

It sounds like you’re in europe so it will be very hard to find, but if you ever see one, pick up a Bell or Northstar canoe. They’re some of the nicest paddling canoes available in terms of speed to stability ratio.


Thanks for advice.

You was no doubt typing this great post when I posted message above. If you read my post above, you will notice that I own a Penobscot 17`, with no intention to trade it.

But your advice on other great canoes will certainly be helpful for other readers that find the shallow arch discussion interesting.

Are you paddling the Norwegian fjords
You have to post some pictures of that - that must be amazing. Penobscot is a versatile that should handle it well, but you’ll be running with the sea kayaks.

Norwegian fjords

– Last Updated: May-15-16 2:18 PM EST –

Sorry to disappoint you, but the fjord in Eastern Norway (canoeing as a teenager) is not the kind of Norwegian fjord as you imagine. Low rolling hills similar to pictures I have seen of Eastern USA and Canada.
A lot of islands and small towns. All my pictures are about camping with beer, booze and hippie girls.

Now I live in Western Norway with the famous fjords within reach. They are dangerous with sudden winds rushing down the mountains. It takes some planning to find emergency landings up front. Mountain walls along shores are common. I am probably too old (read lack of exercise) for this now. The Penobscot 17 is no doubt capable of a trip like this.

Now I am canoeing on small lake called Lutsi. Lot of small islands. Only a portage of minutes (crossing a road) to next lake.

Checking the map, there is a river down from these lakes to a well protected fjord branch running north/south with a zillon small islands scattered around. I do not paddle rivers, and not sure about length and difficulty of portaging. But this will be a great longer trip.

Norway is similar to Canada as a canoeing paradise. Hope I will be a more active photographer, and share with you.

Lake Lutsi at sunset. Penobscot resting in the grass

Edit. Should work now

Penobscot is fine canoe
You are a lucky fellow to own a Penobscot 17. It is a fine and versatile canoe that will serve you well in many conditions. It is not particularly “tippy”. The advice offered above about keeping your head and upper body inside the gunwales takes care of most of your worries. You can give yourself a bit of extra confidence if you’ll try this: With just yourself in the boat, kneel just aft of the portage yoke with knees spread fairly wide. Then apply pressure first to one knee and then the other while keeping your spine vertical (parallel to the tree trunks). You’ll find that you can roll the boat dramatically from side to side with good control and without worrying about tipping it. It will give you a good feel for how far the boat will go without swamping and impress upon you how much better your control is when kneeling than sitting.

Incidentally, I do own a Penobscot 17 and have installed a kneeling thwart which I use to solo the boat. It is a bit big for sure, but it is doable.

Nice picture. The canoe, made in Maine, should feel right at home.


Close to a conclusion.
Those guys that claim a design flaw (in some reviews) are wrong. And none defended this view in this thread.

It takes no special skill, just normal, sound behaviour to make a shallow arc canoe safe. The secondary stability is better than you may expect.

Again- I really appreciate all info and advice in this thread. Please add more if you want.

Hope new potential buyers that will be scared of a negative review, will search more and read this thread.

shallow arch covers a lot of ground
Canoe hull bottom cross sections are typically categorized as round bottomed, shallow V, flat, or shallow arch. But there is tremendous variation in the cross sectional contours of boats categorized as “shallow arch”.

And as pointed out by kayakmedic, when it comes to secondary stability, the side contour is as important or more important than the bottom configuration. Boats with extreme flare, like the Lotus Dandy, or with elliptical bottom contours and shouldered tumblehome like the Bell/Placid/Colden “fire” series heel over very predictably and have great secondary stability. Others with bubble-sided tumblehome that recurves fairly low down will pass through the limit of secondary stability much more quickly and abruptly.

As an example, you initially said you had an Old Town Penobscot 174 RX. There is no such boat. It is now clear you have a Penobscot 17 RX. The triple-layer polyethylene Penobscot/Allagash/Discovery 174 is a very different boat, quite apart from material. Although both are categorized as shallow arch hulls, the poly 174 has a much flatter bottom with relatively straight sides in comparison to the Royalex Penobscot 17. The 174 is a big boat that most would consider stable, but if radically heeled I would suspect it to have less secondary stability than the Penobscot 17.

A couple of thoughts
The fact that people can learn to keep any canoe upright does not mean they are all equally stable. That area between the rails where you keep your head is not of equal width in various canoes. Width matters too.

Though many canoes are clearly very flat bottomed “shallow arch” is the marketable term. Hence anything with a curved chine is called shallow arch in the catalog.

I’ve many boats called
Shallow arch

The kinder ones are like the long sides of an ellipse

The sporty ones are darn near an arc of a tightly radiused circle