: I need some help...first time kayak builder...I stretched the
: LITTLE AUK to 11'4" and now I am ready to cut the cockpit
: out...I'm not very smart on the calculations on figuring were
: the "Center of Buoyancy" would be for this kayak. Thus
: giving me the correct location for the cut out... If anyone out
: there can help me with this calcuation, I sure would appreciate
: it...I guess I should have stuck with the original
: plans.......Thanks.......Gordon

Hi Eric,
Its a question of volume.
You have to find the point at which you have an equal amount of submerged volume fore and aft of a line.
In other words you will have to know how deep it will sink in the water and calculate the total submerged volume and then find the mid point.
Its not that easy to do without software.

An approximate way is to make a rectangle of the water line length and width of the boat and depth below the waterline.
Calculate the volume of that rectangle.
Draw this rectangle to scale on graph paper, each square will represent a percentage of the volume.
e.g a rectangle of 4m X .7m x .05m = .14m cube divided by the number of squares in the rectangle will give you the cubic value of each square.
Add up all the squares inside the hull line (there will be a number of half squares etc.) and you will have roughly the submerged volume.
Count half that number of squares from either end counting all the squares across the hull width and you should have roughly the CG, at least good enough to cut out the cockpit.
This is scratching my memory from maths class from 45 years plus ago so use with caution.
JohnK

Superimpose the shape of the boat on the rectangle, subtract all those squares that are outside the shape (or count all those squares inside the boat) and you will have roughly the volume of your boat.