Swede form vs. boat trim.

[Idiot Savant]

As a canoe increases in speed, relative to the water it is passing through, the bow tends to rise and the stern squat. This is more pronounced the shallower the water.
To counteract this, racing canoes and performance lake tripping canoes are Swede form, meaning their widest point is aft of center.
I've also read, in a number of places, that you should trim your boat slightly bow heavy, especially in shallow water, for the same reason.
One of those places I read this is a book on canoe racing, so I know this advice isn't meant just for boats that aren't already Swede form.
So, I have two questions:
1-should Swede form be even more pronounced so you only need to trim bow heavy in shallow water?
or
2-is boat trim a better solution to the problem in the first place?

 

[Sweetfancymoses]

Swede Form has always been a concern of mine. (Sorry I couldn't resist.)

 

[Idiot Savant]

Swede Form has always been a concern of mine. (Sorry I couldn't resist.)

Concern or interest ?

 

[Nick Pending]

As a canoe increases in speed, relative to the water it is passing through, the bow tends to rise and the stern squat. This is more pronounced the shallower the water.
To counteract this, racing canoes and performance lake tripping canoes are Swede form, meaning their widest point is aft of center.
I've also read, in a number of places, that you should trim your boat slightly bow heavy, especially in shallow water, for the same reason.
One of those places I read this is a book on canoe racing, so I know this advice isn't meant just for boats that aren't already Swede form.
So, I have two questions:
1-should Swede form be even more pronounced so you only need to trim bow heavy in shallow water?
or
2-is boat trim a better solution to the problem in the first place?

I can't see the symmetrical vs. Swede form thing being that much of an issue because it can't be changed while paddling. Paddlers can change boat trim while on the move. If you're going on a mostly deep-water trip (lakes or big rivers), a symmetrical hull is fine (if you have one). For mostly shallow water trips like smaller rivers and streams, an asymmetrical boat (Swede form) is better, but it can still have the trim changed while on the move if necessary. This only really matters when the canoe is moving quickly, especially when near designed hull speed. If you're primarily a "go-fast" paddler, you'd better have a quiver of boats so you can choose the best one for a given trip and still use trim -- the only easily changed variable -- to modify it. Trim is the only real solution to the problem that I can see. I'm sometimes in a hurry, but not usually, so it doesn't matter to me.

I'm not a Facebonk member so I couldn't see the pic(s) at the alternative Swede form link offering, but I googled "Swedish Bikini Team" and found some that weren't restricted in case there are others who don't do much social media.

 

[Jim Dodd]

I agree with Nick.

Over the years, I experimented with adjusting my forms on my strippers.
Trying to get an improvement, in speed, without stretching the original design.
I started by stretching the forward form spacing, and reducing the stern section form spacing.

I couldn't decern any significant difference, at least not an improvement.

Since I have stayed with building symmetrical hulls, with the exception of Bruce Kunz's Merlin, and it's big brother, the 38 Spl., which have a slight Asymmetry to them.

My experiments were done with straight keeled designs.
Rockered hulls may be a different story.
I have seen a few hulls, that were rockered more in the front, than the back. An attempt to find a good marriage between rocker and not. I don't see how this can work, either.

Speed and Rocker don't go together.
Length increases speed, to a point, and reduces maneuvering.

A Quiver of canoes as Nick states, is good to pick the right canoe for the situation.

Jim

 

[Boatman53]

I took the lines from an old Guideboat a long time ago and it was fuller in the stern than the bow. I reasoned that it might have been built by a skinny guide that had well nourished clients. But maybe he just worked in shallow water, I’ll never know.
Jim

 

[Idiot Savant]

I can't see the symmetrical vs. Swede form thing being that much of an issue because it can't be changed while paddling. Paddlers can change boat trim while on the move. If you're going on a mostly deep-water trip (lakes or big rivers), a symmetrical hull is fine (if you have one). For mostly shallow water trips like smaller rivers and streams, an asymmetrical boat (Swede form) is better, but it can still have the trim changed while on the move if necessary. This only really matters when the canoe is moving quickly, especially when near designed hull speed. If you're primarily a "go-fast" paddler, you'd better have a quiver of boats so you can choose the best one for a given trip and still use trim -- the only easily changed variable -- to modify it. Trim is the only real solution to the problem that I can see. I'm sometimes in a hurry, but not usually, so it doesn't matter to me.

I'm not a Facebonk member so I couldn't see the pic(s) at the alternative Swede form link offering, but I googled "Swedish Bikini Team" and found some that weren't restricted in case there are others who don't do much social media.

It's more of an academic question.
Could be a consideration when buying a canoe or kayak.
All racing canoes and Boundary Waters type boats are Swede form. There is obviously a difference, but at what speed does it become an issue?
I have a theory that, at very low speeds in deep water, fish form might actually produce less drag.
For me the concern is shallow water. Fall is the favored time to paddle the Green and Colorado, in Utah, when water levels are low and sandbar camping is at it's best.
I've always favored loading my canoes slightly stern heavy, unless I have a head wind or something.
I may rethink that. At least in shallow water.

 

[Mason]

Unless you're performance paddling, I wouldn't worry about it. I've raced in shallow water races, and have paddled my asymmetrical Wenonah WWC1 (which is designed specifically for shallow water) in a lot of "suck water" over the years. Rapid, short strokes and trimming bow heavy (sliding forward on my sliding seat) makes a noticeable difference, but I'm an obligate performance bent-shafter. If you're already stern heavy, shallow water performance (there's that term again) will be lessened. On the Green River (did it in 2000), I'd worry more about getting stuck on a sandbar than ultimate shallow water efficiency. Stern heavy will get you stuck worse--more boat will pass over the sandbar rather than the bow plowing into it.

 

[Idiot Savant]

Unless you're performance paddling, I wouldn't worry about it. I've raced in shallow water races, and have paddled my asymmetrical Wenonah WWC1 (which is designed specifically for shallow water) in a lot of "suck water" over the years. Rapid, short strokes and trimming bow heavy (sliding forward on my sliding seat) makes a noticeable difference, but I'm an obligate performance bent-shafter. If you're already stern heavy, shallow water performance (there's that term again) will be lessened. On the Green River (did it in 2000), I'd worry more about getting stuck on a sandbar than ultimate shallow water efficiency. Stern heavy will get you stuck worse--more boat will pass over the sandbar rather than the bow plowing into it.

I think canoes, in general, handle better if slightly stern heavy.
Is it worth it to give up some handling to gain some speed?
I've been on club trips where I've paddled what should have been the slowest boat and been at the front of the pack and I've been on trips where I probably had the fastest boat and been near the back.
Was how the canoes were trimmed a factor?
Looking back on it, I think it's a solid maybe.

 

[Glenn MacGrady]

Here is a classic 1999 discussion about the advantages of swede form vs. fish form, and how boats part water and make waves. The discussion is mostly in the context of kayaks, but I don't see many reasons why it wouldn't apply equally to canoes and ships. The participants in the discussion are Matt Broze of (swede form) Mariner Kayaks, naval architect and boat designer John Winters, and boat designers Nick Schade and Dave Kruger among others. It's a long and technical debate, but very interesting for anyone interested in hydrodynamic physics.

In the second post, Matt Broze presents and summarizes his arguments as to why he considers the swede form hull to be superior. John Winters then chips in and the discussion is then off to the races, both figuratively and literally.

PaddleWise - Pros/Cons of Swede Form

A listserve and site about seakayaking and other watersports with emphasis on paddling safety, navigation and seamanship, equipment and the marine environment and conservation issues.

www.paddlewise.com

 

[Bob B.]

Swede form vs symmetrical ... I remember many excellent paddlers telling me my old timey ways are ridiculous, Swede form is the only way a serious tripper should travel - it is faster, quicker, more efficient ... etc. I suppose they are correct, but those attributes are not what does it for me as a canoeist. As a solo tripper who also travels with a dog - and now a dog that with age gets uncomfortable and moves about in the canoe often, I still find I have a significant preference for symmetrical hulls. I paddle a tandem from the bow - backwards with dog and most gear in front of me. I prefer maneuverability and ease of turning, one sided paddling and predictability in adverse conditions over modern designs. I really dislike a skegged stern and find that is what I get with a modern hull, even though they are quicker, faster and often have excellent glide and efficiency.

All that said, I think the OP is correct in the concept of trim. I think symmetrical hulls are less sensitive to trim, especially in a tandem paddled solo. That really may be the main difference. Conditions on a trip can change many times on the same day - from a shallow creek with current, to a large windswept bay with wind in your face, to rounding a corner and hitting the larger part of the lake with wind and waves on your stern quarter. Often times the Swede form will want to weather cock and trim changes need to be made on the fly. My symmetrical shape is much less sensitive to the changing conditions, and may require a different paddle stroke on occasion, but basically we just keep paddling without the need ( very often ) to rearrange gear for a trim change.

Lastly, the OP started this post talking about canoe speed and bow rise, stern squat. Traveling solo I never really worry about speed - I think I paddle too slow, even empty with just my dog and I to notice much. I trim the boat so I have what I deem to be a maneuverable, good in wind, efficient canoe ... and seldom need to change no matter the conditions. In fact, I find my Prospector 15 Ranger and my Eaglet - both symmetrical hulls - to be the most efficient, maneuverable predictable hulls I have. Paddled loaded or empty, current - wind - flat water, they are the easiest to trim, thus the easiest for me to paddle.

Bob.

 

[Jim Dodd]

Here is a classic 1999 discussion about the advantages of swede form vs. fish form, and how boats part water and make waves. The discussion is mostly in the context of kayaks, but I don't see many reasons why it wouldn't apply equally to canoes and ships. The participants in the discussion are Matt Broze of (swede form) Mariner Kayaks, naval architect and boat designer John Winters, and boat designers Nick Schade and Dave Kruger among others. It's a long and technical debate, but very interesting for anyone interested in hydrodynamic physics.

In the second post, Matt Broze presents and summarizes his arguments as to why he considers the swede form hull to be superior. John Winters then chips in and the discussion is then off to the races, both figuratively and literally.

PaddleWise - Pros/Cons of Swede Form

A listserve and site about seakayaking and other watersports with emphasis on paddling safety, navigation and seamanship, equipment and the marine environment and conservation issues.

www.paddlewise.com

Wow what a discussion !!!
Honest to say, I was lost after a short time.

The discussions centered around water flow around an object.
Fine ! but they ignored the propulsion side of it.
A canoe, or kayak for that matter, is pushed forward from the side.
An outboard, or a ship, is propelled from the middle of the stern.
To me this changes the dynamics all together.

Dragging a hull through a tank is also different, than paddling with a blade.

All I know, is the first boat to the finish line is the winner. The paddler is the reason it is there.

Last thought. My first canoe, is 14.5' foot long, and 35" wide ! It paddles like a Dog !
Until you heeled it to one side ! You can paddle all day long, on one side, and go as straight as an arrow.

Jim

 

[Boatman53]

Since Jim brought up paddling it reminded me that Gondolas are asymmetrical, not bow and stern but port and starboard. The two halves of the boat have different shapes because the propulsion (rowing) is always on one side And the asymmetry accounts for that.
Jim

 

[Idiot Savant]

Here is a classic 1999 discussion about the advantages of swede form vs. fish form, and how boats part water and make waves. The discussion is mostly in the context of kayaks, but I don't see many reasons why it wouldn't apply equally to canoes and ships. The participants in the discussion are Matt Broze of (swede form) Mariner Kayaks, naval architect and boat designer John Winters, and boat designers Nick Schade and Dave Kruger among others. It's a long and technical debate, but very interesting for anyone interested in hydrodynamic physics.

In the second post, Matt Broze presents and summarizes his arguments as to why he considers the swede form hull to be superior. John Winters then chips in and the discussion is then off to the races, both figuratively and literally.

PaddleWise - Pros/Cons of Swede Form

A listserve and site about seakayaking and other watersports with emphasis on paddling safety, navigation and seamanship, equipment and the marine environment and conservation issues.

www.paddlewise.com

I'm well aware that Swede form has been determined to be faster than fish form and have seen that article before. John Winters has a website with some good articles on canoe design.
But I think there could be an argument for fish form at low speeds when wave making resistance is less important.
I have nine boats. Only one isn't Swede form and it's symmetrical, not fish form.
My question was whether taking Swede form even further, that is moving the widest point even farther back, might not be better for the shallow water rivers I mostly paddle. Or, alternatively, start loading my canoes more bow heavy.

 

[Jim Dodd]

I'm sure Charlie Wilson will remember. Betty Ketter.
Betties family were a race oriented family, and sold Wenonah canoes at their place on the Mississippi, in St Paul Mn.
Betty , in conversation stated, it's not the canoe. It's the paddler and his skill.

She told a story, how her and another female, easily paddled past a couple of buff college boys, in a race. Afterwards the much younger paddlers asked Betty how she did it. Knowing how to paddle was more important than strength, was her reply.

As I look back at a few canoe designers I've met. Bruce Kunz, Bob Brown, and David Youst. They all fell into the smaller statue category.

Maybe the reason they all designed smaller canoes, at least in the beginning.

I'm still impressed by Bruce Kunz,s 38 Spl. , and DY's Magic.

Thanks Glenn and others for bringing this thread to light.

Jim

 

[Glenn MacGrady]

My question was whether taking Swede form even further, that is moving the widest point even farther back, might not be better for the shallow water rivers I mostly paddle. Or, alternatively, start loading my canoes more bow heavy.

Personally, at the modest recreational speeds I paddle, I don't worry about stern squat in shallow water and don't think it matters much whether a canoe is symmetrical or slightly swede form. I'd prefer a symmetrical canoe if I were paddling it backwards from the bow seat, and I would prefer symmetrical for a highly maneuverable canoe (whitewater, twisty streams, freestyle play).

A radically swede form hull would probably appeal only to a small niche of canoeists, mainly racers.

I don't think shifting ballast can accomplish all the things that waterline shape can. It can't change the design waterline or gunwale lines. It can't change the amount of flare or tumblehome that might accompany a symmetrical, fish form or swede form waterline.

Experimenting with ballast shifts in different water and wind conditions can be informative and can sometimes result in performance improvements in any hull design. When paddling long, straight distances I prefer to be a bit stern heavy, and a swede form waterline can help here too; whereas when I'm paddling the twisties, I may prefer to be a bit bow heavy to loosen the stern for heeled turns. A sliding solo seat can be helpful to make such ballast shifts easy and on-the-fly because usually the primary ballast item is one's body weight.