In a recent post, you gave two different definitions of prismatic coefficient - one was not correct.
This one is incorrect - this one is the definition of block coefficient.
Prismatic Coefficient is a mathematical measurement of the relative shape of the bow and stern of the boat. It displays the ratio of the underwater volume of the hull relative to a rectangular block.
And this is the correct one:
We express the "full hull" property by the prismatic coefficient, which is the ratio of volume displaced to the product of waterline length and maximum cross-sectional area.