so, in the market for a boat and am wondering what these two options provide, and what they dont. Thanks.
flared sides keep out waves better
tumblehome keeps your paddle closer to the center of the boat.
Flair and Tumblehome
My favorite boats always have some of each. I prefer flared ends with a high coefficient of volume to ride over waves with less water entering the boat. I like tumblehome amidships to give the boat a wider stance at the waterline, and a slim profile at the rails.
flare verse tumblehome
Flare is certainly drier, but it turns out the key part of dryness in hull desigh is fullness just above the waterline.
Tumblehome improved the paddlers position - making it far easier to get both hands across the rail and present a vertical paddleshaft which induces less yaw and easts less energy.
Tumblehome tends to limit secondary stability, ecause, as a heel angle increases, eventually less hull volume is being placed in the water.
Best of both worlds is shouldered tumblehome as seen first on DY designed Curtis hulls and everything in that family,[ Bell, Hemlock, Pb,] but also Scarborough designed Dagger Canoes, Winters designed Swift, etc.
Not so sure about generalizing that increased tumblehome and lower secondary stability go hand in hand. There is certainly a point at high angles of heel where this happens, but that is a pretty steep angle.
Tumblehome, espcially mid-shops is so user friendly that I wonder why more designs do not incorporate it. Does it have to do with getting the boat out of the mold?
Yes, that is one thing. Another is it
increases shipping costs in cheaper boats that are shipped stacked and assembled at store. Another is more difficult and time consuming, therefore more expensive to lay up. Those reverse curves can be a bitch to lay. Etc …
decreased secondary of tumblehome
… is more pronounced with greater loads. You run out of “more boat in the water” quicker as you rotate because there is more boat in the water to start with.
Problems with tumblehome
Mick is quite correct. Significant tumblehome requires a two piece mold with bolting/ unbolting, tapeing the bottom seam issues , not to mention sealing another flange for infusion.
Applying gel to the upside down part is always a difficult spray job.
The layin itself is more complicated with greater chance of bridging.
The resultant hull can have a narrower paddling station and be drier than a constant flare hull if vulume is brought pretty high and the tumblehome shaped to throw water uptwards rather than back into the paddlers lap.
We heel a hull to encance turning by lifting the stems: all heels. therefore, are to the rail for maximum effect.
Sharp tumblehome, as on USCA race boats is prone to get you. Once the knife edge wing in underwater, progressively less volume is placed in the watewr as the heel continues.
Yost bubble tumblehome, as on Sawyers and some early Curtis hulls, is fine until you bury the widest part of the hull. From that point on, as less volume is forced into the water, pushing a heel becomes a progressive enterprise.
Later Yost/ Galt/ Scarborough "Shouldered Tumblehome" designs: Curtis, Bell, Hemlock, Pb, Lotus caper, several Daggers, get firmer as the heel progresses, until the shoulder itself goes underwater. From that point, same rules apply: less volume in the water, less predictable heel.
On the otherhand, to crank a 270 degree turn in Flash or WildFire, the shoulder must be buried to the rail, the extra degrees of heel really freeing the stems up ezxcitingly.
thanks all for the info, but who…
makes a canoe flared at the ends with tumblehome midship? What companies, that is…
didn’t mean there was no secondary
… just that more is more and less is less, all other things being equal.
A duffer like me can sink the gunnel of a Supernova underwater and bring it back up. But I can’t do it with a Wildfire.
Bell, Curtis nlib, Dagger nlib, Hemlock, Placid boats, Swift, Wenonah.
it's always a balance. speed typically indicates a tender boat, but not always. wide is slow and long is fast, etc. from there it's all about trade-offs. tumblehome and flare are both great things. my favorite canoes incorporate both.