Hi

This is tradisional boatsbuilding , you make a number of sections from
the drawing and place them how the drawing show the sections. Then you
divide the edges of the sections into how many panels and then use a
strait thin board that you nail onto the sections , where it get
impossible to make the board follow the expected midline of the panel,
you simply nail a new thin board and let it point in the right
direction. --- Then you measure up and down from the edges of the board
and note the measures where they are taken.
When that's done you take off the board and place it ontop the plywood
sheet and make marks from the measures you made --- connect the marks
and the shape shuld be right.
Just one way.