Length
It is a question of physics.
But you don't have to be a whiz in physics to understand that
a narrow and longer hull generates less friction against the
water and is easier to paddle.
Some people say that the center
half of a well-designed hull provides 75% of its stability
and carrying capacity. The primary function of the bow and
stern if to part the water at the entry and the exit.
In most cases, the greater the
waterline length and the higher the ratio of length to width,
the faster the canoe will go and the easier it will be to
paddle.
It is also said that the maximum
speed equals 4.5 times the square root of the waterline length
in depth water. I have not tested it so far!
Hull Shape
The hull views gives you an indication of
the watercraft's utility. Was it built primarily to be used
on a lake, a flat river, or in whitewater? Can the canoe be
used for trips, wilderness waters, or just for daily recreation?
We all know that a canoe can be used for many purposes - it
is a versatile craft - but if you think your canoe will be
used primarily for a specific need, why not get immediately
a canoe for this need? (See the section Your
Interests)
It is important to understand how a rounded-bottom and a
flat-bottom canoe behave in waves and their overall stability.
 A
canoe with a rounded-bottom hull will go deeper
in the water. The waves will tend to go under the hull.
This type of canoe will have a better final stability.
You can manoeuvre it to prevent capsizing. |
 A
canoe with a flat-bottom should be used only
on calm waters or to carry loads. It's final stability
being very poor, it should not be used for recreation.
It could capsize without warning. |
Even if you're not an expert,
you will certainly appreciate the subtle changes of
these basic forms. The way the hull of a canoe is built has
a major impact on speed, load, manoeuvrability, tracking in
water and stability.
Profile View
The figures shown below span two extremes,
from an extreme rocker canoe to a straight keel line canoe.
As previously mentioned, each constituent in the design has
an impact on the manoeuvrability, speed, tracking, stability
and ease of paddling of the craft.
For example, if you select an extreme rocker
canoe, which will give you optimal manoeuvrability, you will
sacrifice tracking and speed.
Let's now discuss some canoe elements that
can be seen on the profile view above.
Keel Line
In looking at the keel line of a canoe, you can have a good
idea of its manoeuvrability, its speed and tracking. If you
imagine that you have a horizontal line at midpoint four (4)
inches (10 cm) over the keel line that will give you an estimate
of the waterline length. An optimal waterline should give
more speed and tracking even if it has a high friction on
water because the draught (traction) will be minimized but
less manoeuvrability to turn quickly in every direction (except
for a flat bottom hull). However, a rocker keel line will
do the opposite because the water line length will be shorter
(see Figures above), which means, more manoeuvrability, less
speed and tracking. A rocker keel line canoe is mainly used
in whitewater because its shorter waterline helps to turn
on its midpoint and rises over waves (See Rocker).
Keel or Not??
The keel is a subject of high controversy for canoers and
manufacturers. We don't really think it helps tracking and
manoeuvrability to an intermediate or experienced canoer.
It can maybe help a novice paddler on a waveless lake or quiet
river. Furthermore, some people unfamiliar with a canoe, believe
it helps stability for not keeling over. This statement is
completely false.
The main purposes of a keel are to stiffen
and give some protection to the hull. But this has little
impact when you cross a sandbank or a shallow. An aluminium
canoe, as an example, is usually made in two (2) parts, and
then the keel is necessary to keep parts together.
As a keel can affect the manoeuvrability of
a canoe, we recommend using a canoe without a keel for high
running water or whitewater.
Rocker
The rocker is the longitudinal curve of the keel
line from bow to stern.
A canoe with a high rocker (see also keel
line) can easily turn at midpoint and rise over waves.
It is then an excellent choice for whitewater. However, it
will be a poor choice for flat water because it will be slow
(no waterline length) and difficult to track in staight-line.
Before choosing a canoe, you should take into
consideration the following:
- A canoe of 15 feet (4.5 meters) or less
needs less rocker. The rocker should not exceed 1,5 inches
(3.8 cm).
- A canoe more than 15 feet (4.5 meters),
usually used for light tripping and recreation, needs more
rocker then a short canoe. The rocker should not exceed
3 inched (7.6 cm).
- A canoe mainly used for running river or
whitewater can have more rocker than the former.
Stem Shape
Many people prefer having a high-recurved stem because it
is graceful and eye appealing. It is a matter of personal
preference. Never forget that a high-recurved stem offers
a large wind surface, which can affect the tracking or manoeuvrability
of a canoe
