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Thursday, October 4, 2012

Bow and Stern Shapes of Dugout Canoes

In 2000, a drought in Florida caused the water level to drop on Newnans Lake, near Gainesville, leading to the discovery of remnants of more than 100 dugout canoes. Fifty five of these canoes were carefully examined and studied, with radiocarbon dating placing 41 of them in the Late Archaic period (2300 to 5000 B.P.) A paper on the findings states:
"The Archaic period canoes from Newnans Lake are indistinguishable from canoes produced in later periods [in Florida, ed.] and are not the crude, short, blunt- ended type thought to represent the earliest dugout canoes." (ARCHAIC PERIOD CANOES FROM NEWNANS LAKE, FLORIDA Ryan J. Wheeler, James J. Miller, Ray M. McGee, Donna Ruhl, Brenda Swann, and Melissa Memory; American Antiquity, Vol. 68, No. 3 [Jul., 2003], pp. 533-551)

The paper included this graphic, comparing the ends of three of the Newnans Lake canoes with a couple canoes found elsewhere in Florida:
(From Wheeler et al. Click any image to magnify.)
This got me thinking about the shapes of the ends of dugout canoes and how, for such a superficially simple technology, they exhibit a tremendous amount of variation, almost as great, perhaps, as that of plank-built boats, which differ worldwide according to local custom, habit, and conditions. (I'm purposely leaving outrigger-equipped dugouts out of this discussion, as the addition of an outrigger affects the canoe's roll stability and directional stability, and these effects might impose or permit even more variables.) 

No doubt the earliest dugouts were blunt-ended, similar to Newnans Lake #19 in the image above, if one accepts that the shaded area in the profile view was indeed present in the boat as built. Regardless of their level of technology, anyone observing the behavior of the water at the bow of this design as the canoe moved forward would have eventually recognized that a smoother shape would be more efficient. The earliest modification was probably to round the ends.

One of the oldest boats of any sort ever discovered, this blunt-bowed dugout, found in the Netherlands, dates to 8500 BC.
Following that, the quest for efficiency might have led in two directions: toward a flat, overhanging bow, or toward a wedge-shaped bow, which might initially have had a straight vertical stem, gradually adopting a sloped, rising shape.
Flat overhanging bow on a Tusipono Embera Indian canoe on the Chagres River, Panama. Photo by Shawn J. Dake, 2011, from Maritime Matters.
I believe the wedge-shaped bow would be more efficient through the water, but the overhanging design has the advantage of being able to be beached bow-in, making loading and unloading easier. In contrast, a wedge-shaped bow with a vertical stem is highly unstable when beached perpendicular to a sloping shoreline.
Wedge-shaped bow and stern with nearly vertical stem and stern posts. Canoe of unknown provenance. From HistoryFaceBook wiki.
It must have been thousands of years before more sophisticated (or decorative) shapes came into use. The overhanging platform shown in the Moon Lake canoe in the top illustration might give a spear fisherman a place to stand forward of the disturbance caused by the stem moving through the water, giving him a crucial few inches in which to make his strike. A similar platform for a poler in the stern would improve his view and ability to navigate through flooded grassland like the Everglades.

A well-rounded bow like the one below provides plenty of buoyancy, while the raking stem allows it to ride easily over small waves. The pinched knob at the very end might make the end more resistant to splitting.
Rounded bow with rising stem and extended, "pinched" end knob. On the Cavally River, Liberia. From reCycling the World blog.
These extended bows below could serve as carrying handles, or to help part the vegetation when moving through a swamp.
Very long, narrow bow extensions on canoes of the Orang Asal people of Malaysia. From My Rainforest Adventures blog.
The heavy, blocky bow here seems to favor durability and simplicity of construction. The stern appears to be somewhat more refined, thinner, but with a transom shape somewhat like the bow. I suspect that, like the bow, the bottom of the stern transom is above the waterline, permitting the smooth wake.
Blocky transom-shaped bow and thinner transom stern on a Canoa Indígena, Casco or Ubá in Brazil's Amazon region. From Brazilian Boats and Canoes blog 
I hesitate to address the variety of bow shapes employed by the First People of the Oregon/Washington/British Columbia region. These were complex, of great variety, and deserve an extended treatment of their own.
Yes, we're looking at the bow of this canoe from the Queen Charlotte Islands, BC, The red triangular member, a kind of forward skeg, would doubtless have contributed to directional stability but might have made maneuvering difficult. Can you comment on other effects or purposes of this interesting feature? From a Ball State University teaching website highlighting material from the National Museum of the American Indian.

1 comment:

  1. Eric McKee in his Working Boats of Britain illustrates dugout end shapes to resist splitting.

    If you look at the logboats excavated at Must Farm
    it may be more than coincidence that the ends follow McKee's dugout round section but in a refined way. They certainly knew wood back then,