Gravity and Buoyancy

There are two important forces gravity and buoyancy that making surfing possible.
Picture by: Paul Dohert
Gravity is a force pulling together all matter (which is anything you can physically touch). The more matter, the more gravity. Gravity is the force pulling you down.

Buoyancy is the upward force that keeps things afloat in liquids. Water exerts a force on the contacting surface of the board. Buoyancy is the force pushing you up.

Archimede's Principle the buoyancy is equal to the weight of the displaced fluid. If object is less dense than fluid :

Newtons first law states that the sum of all the forces is equal to zero, this is called the net force, so if there is no movement or acceleration there is no net force.

The gravitational force and the buoyancy force are equal and opposite. The net force of the sufer plus the board is equal to zero.