Measuring
Boats
By
Peter Coates
November 26, 2006
There are a number of measurements that
are going to be taken of boats. Some
are easy, line overall length, and gunnel heights, so I wont describe
them. Some
are a bit harder.
The hard ones are the 4 waterline
width and length, or the 6 waterline
width for voyageurs.
The
4 waterline length
The
boat is places on a flat surface, and
a couple of prepared 4x4s are arranged
bow and stern. I use a couple of r3 lengths of rough 4x4 that
have been sanded so they are square,
and then have one edge planed to form
the top inside edge that is exactly
4 off the ground.
Prepared
4x4 showing bevelled edge
If
the boat has a V hull, you will need
someone to help hold the boat straight.
If
the rudder is in the way, then measure
including the rudder, and use a tape
measure to estimate how much to subtract
afterwards. If the boat has a long Greenland
style prow, it is a bit of a judgement
call exactly where the front is. You must not lift the boat off the ground as
you tuck the 4x4 in. Be
fairly generous with the length to be
safe.
4x4
at bow of boat
4x4
at stern of boat
Lift
the boat out from the 4x4s, and measure
the distance between them. I
take 2 measurements, one on the left
and one on the right and average them:
that compensates for any small angle
the 4x4s might have been at. Note this number.
The
4 waterline width
This
will be measured with a calliper. A similar calliper can be made quite cheaply
from a metre rule and a few pieces of
thin timber.
The
4 Calliper
Detail
of the slider
Detail
of the fixed arm
The
boat being measured is placed upside
down. If it is a tandem, two 4x4s are arranged across
the two cockpits, if it is s solo, then
just the one 4x4 is used. This is to ensure that the boat is properly aligned
up side down.
Then open the calliper to the
minimum width allowed, and place it
square over the inverted hull. Slide it fore and aft until you find the widest
part of the hull. If
the jaws fail both to touch the hull
at some point, the boat is too narrow.
The
jaws of the calliper are not in contact:
ILLEGAL
The
shaft has risen off the hull, both jaws
are in contact: LEGAL
jaws
and shaft in contact. Exact measurement, or BARELY LEGAL
Email
info@yukonriverquest.com
if you have any questions.
