Waterplane coefficient 

It is the waterplane area divided by the area of the surrounding rectangle. A high waterplane area means the area of the waterplane is more which implies stability will be high during rough weather. The area surrounding it will be the rectangle made by the ship's water plane. The figure below will illustrate the concept clearly.  



Prismatic coefficient 


It is the volume of water which is displaced when the ship is immersed divided by the volume of the surrounding prism. It is the ratio between underwater volume to product of the maximum length of the ship and area of largest cross-section. A low prismatic coefficient indicates that the mid mid-ship section is broader while the ends are fine. 


Block Coefficient 


The block coefficient is the ratio of the volume of water displaced by a ship to the product of length, breadth and draft. For an oil tanker, the block coefficient is 0.9-0.95, while the sailing ship has a low block coefficient.


Tonne per centimeter (TPC)


Tonnes per centimeter of immersion is the amount of cargo that can be loaded so that a ship can immerse by 1 cm.