: You might want to consider using the KayakFoundry software to
: design your kayak to a closely match a kayak of your choice.
: (not an exact replicate of course). I have designed a kayak
: using this software to try an replicate a favorite kayak. In the
: software you basically use your mouse to push and pull on points
: to get the length, width, and hull/deck shape. Start by
: measuring the overall length, width and height of your current
: kayak. Measure at every one foot increments deck/hull width and
: height (develop a table). Approximately measure rocker for both
: bow and stern( The CAD software will show you where to measure
: for rocker). Using the KayakFoundry software adjust your CAD
: design. Now you can use the hull/deck control points of the
: software to shape your kayak to your liking or design. This is
: the approximation of your favorite kayak. You can also fine tune
: the design by printing out mid-point stations( 3,4 forward and
: 10,11 stern) forward and aft with the software and fit them to
: your kayak you are replicating. Make adjustment as necessary,
: re-print station and test fit again for the shape. Make sure you
: calibrate your printer to the software. You can also view hydro
: static charts and table to see how your design changes affect
: the kayaks performance.

: If you have a computer, it is easer to sit down at the computer
: designing for a couples hours versus trying using jigs to
: replicate the form. The problem with the jigs is nailing down
: where the waterline is. This software is easy to use; it took me
: a couple of hours to complete my first prototype!
: http://www.blueheronkayaks.com/kayak/index.html

: Hopefully this helps!
: Kevin

Waterline is pretty easy if you already have the boat :)

Sit in the boat in the water and have someone walk around it with a crayon.

Bill H.