: Yes, I do prefer to build him a S&G. He is
: 4'6" and currently weighs in at 78lbs. As any parent of a growing
: child, I am looking to get maximum use (something that he will not outgrow
: too quickly) from his kayak.

One answer with a sea kayak is to remember that it has cargo space. You can
use ballast when the paddler is small and light and lose that ballast when
he grows. Ballast adds stability, so you can build a narrower boat than a
beginner might take to empty, which will also give a speed advantage which
is useful for a paddler with a lot less muscle mass than an adult. With a
shorter boat, the hull speed is less and you would not expect the achievable
top speed to match that of an adult boat, but cruising speed and overall
effort for a day of relaxed paddling are likely to be more important, and
these can be optimised with a slim ballasted boat rather than a stable tub.

Having said all that, you do need a boat which will FIT - a loose boat will
be harder to control and be a frustrating experience...

Unless you plan to build from a kit, you don't need to restrict yourself to
designs specifically aimed at kids - you can scale a design to fit. With
stitch and glue, you will have to scale length, beam and depth by the same
factor (if you want half the displacement, for example, scale all three
by dividing by the cube root of two). With a stripper, it is easier to
scale by slightly differing factors in each direction, so you can reduce the
depth a bit more than you reduce the length, perhaps. I didn't do that with
the boat I built - it was just a straight scaledown.

I built my daughter a Guillemot Great Auk, straight from Nick's book, but
scaled down by 5/6, which does yield something very close to 14' long. She
was just about able to paddle it aged seven, and the displacement is such
that her mum can paddle it without exceeding the design displacement by more
than a fraction. It's now looking as though Sarah will be a bit bigger than
her mum when grown up, so the boat may not last her beyond her teens, but
she is currently looking more to doing freestyle whitewater than sea trips
anyway ...

One issue with scaling is that you might find the cockpit does not match an
off-the-shelf spraydeck. I had to get one made up especially for Geyrfugl,
but this just took extra time, rather than actually costing any extra, so
was not really an issue (except the deck won't fit any other boat, and we
don't have a spare, apart from an adjustable nylon one).

The pic shows Sarah's friend Heather (three years older than Sarah, and just
short of her twelfth birthday when this trip took place) paddling Geyrfugl
on the 2005 Conwy ascent.

Andy