Re: [Paddlewise] Ballast and trim question

From: Robert Livingston & Pam Martin <bearboat2_at_attbi.com>
Date: Mon, 19 Aug 2002 06:58:43 -0700
> My question to you is how much weight and whether to move the seat to the
> forward mounted position, which the Quest includes as a design option.

It is somewhat sad to have to resort to using ballast to overcome what are
ultimately design flaws of a kayak for the particular user.

Adding weight slows you down (increased wetted surface for one). Imagine
asking a racer if he would mind carrying an extra 50 lbs.

If you are going to add weight to a boat it might be nicer to make the hull
stronger by adding a few layers of glass. There is something weird about the
builder working hard to shave a few pounds and then have the user add 50 lbs
of ballast. 

If you are trying to get a more stable boat, it might be nice to add an inch
to the width rather than add ballast.



But accepting that the purchase decisions have been made and the situation
is not perceived as acceptable for the unloaded boat...

Where the ballast should go (except at the bottom of the boat :)  ) is
difficult to say without being familiar with the specifics of the boat in
question. The designer might have had a specific center of buoyancy in mind
for a "trimmed" boat. That may or may not have been under the lap of the
paddler (the approx center of gravity of the paddler)  Perhaps the design
"trimmed" boat had the center of buoyancy elsewhere depending on the
designer's understanding of the typical loading of the kayak. Or perhaps the
designer did not know where the center of buoyancy was.

A guess would  be to center the ballast under the vertical plane of the
anterior surface of the abdomen. To be more precise, you could experiment by
putting yourself in the unloaded boat in still water and moving the ballast
while looking  at a carpenter's level placed along the keel line. Most
kayaks are designed with "trim" being the state that has the mid-keel line
horizontal.

As for the amount of ballast, the answer almost has to be the "least that
you can get away with"

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Received on Mon Aug 19 2002 - 06:58:58 PDT

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