Center of Gravity and Buoyancy
Stability  the center of gravity vs. the center of buoyancy.
 Center of Gravity is the point in a body where the gravitational force may be taken to act
 Center of Buoyancy is the center of gravity for the volume of water which a hull displaces
When the hull is upright the center of gravity and center of buoyancy are on the same vertical line, and the hull is
 stable
For most hulls the center of buoyancy is below the center of gravity and the hull is said to be metastable.
When the hull tilts the center of gravity remains in the same position related to the hull (as long as the hull is not changed and/or the cargo is not moved). The center of buoyancy will move to fit the new center of gravity for the volume of water replaced by the hull. In the beginning the gravity force and the buoyancy force will create a
 righting torque
that tries to move the hull back to the upright position.
If the hull is tilted to much the center of buoyancy will move to a position where the buoyancy and gravitation force starts to create a moment that work in the same direction and the hull will
 capsize
Related Topics

Fluid Mechanics
The study of fluids  liquids and gases. Involving velocity, pressure, density and temperature as functions of space and time. 
Mechanics
Forces, acceleration, displacement, vectors, motion, momentum, energy of objects and more. 
Statics
Loads  forces and torque, beams and columns.
Related Documents

Acceleration of Gravity and Newton's Second Law
Acceleration of gravity and Newton's Second Law  SI and Imperial units. 
Buoyancy
Buoyancy is the resultant force acting on a submerged body. 
Center Mass
Calculate position of center mass. 
Center of Gravity
A body and the center of gravity. 
Hydrostatic Force acting on Submerged Surface
Calculate the thrust force acting on a submerged surface. 
Shipping Measuring Units
Vessel and cargo capacities. 
Torque or Moment of Force  Online Converter
Torque or moment  the tendency of a force to rotate an object. 
Universal Gravitational Law
Gravitational attraction between two objects vs. mass of the objects and the distance between them.