D/L ratio is the displacement in long tons (2,240 pounds) divided by the *cube* of (the length at the waterline in feet divided by 100) - should be greater than 270 for sea-going trawlers.
A/B ratio is the ratio of the area of the vessel above the waterline to that below the waterline - 2.1 to 2.6 desirable, the lower the better.
PC is the Prismatic Coefficient - the ratio of the volume of the hull underwater to what it *would* be if the largest section were carried the full length of the waterline - value must be matched to the D/L ratio.
L. C. B. is the Longitudinal Center of Buoyancy
L. C. F. is the Longitudinal Center of Floatation. This is the point around which the boat effectively pivots when weight is shifted fore and aft.
GM is the distance from the center of gravity (G) to the metacentric height (M). (Note, it MUST be positive!)