Angle of Vanishing Stability (AVS)

Angle of Vanishing Stability
There is a lot of mystery about what exactly the Angle of Vanishing Stability represents. In short it gives you an idea about the stability of your Yacht. How stiff or tender she will be in a heavy sea.
A vessel is said to be:-
• “stiff” if she strongly resists heeling and
• “tender” if she heels more readily:
Ideally the AVS for vessels should be more than:

Once capsized, many vessels become stable in the inverted position. 

The angle of Vanishing Stability
As the boat heels more, RM decreases, until RM (righting movement) is zero. The boat can invert!
Righting moment curve for flat water.

The above diagram tells us that if a boat heels far enough, it becomes stable upside down.
The point where this occurs is known as the Angle of Vanishing Stability or AVS.
Boats will not normally heel past their AVS. Obviously, the wind could not make this happen, the sails are under water and the only way for this to occur is for the force of the water to push the boat over.
A vessel which inverts will remain inverted until a wave rolls it past its angle of vanishing stability, then it will return to the correct orientation.
Therefore the higher the AVS is the more stable and resistant to staying inverted it will be.
Cool Change, my  Moody 45DSe has an AVS of 180!
For more info on Stability click here...