Why does the axis of rotation pass through the metacentre?

[reterty]

When a ship heels, the centre of buoyancy of the ship moves laterally. It might also move up or down with respect to the water line. The point at which a vertical line through the heeled centre of buoyancy crosses the line through the original, vertical centre of buoyancy is called the metacentre. But how can we prove that point, about which the ship rotates (starts oscillating for the small angular displacements), is the metacentre?

 

[LURCH]

I don’t think it is. When a ship heels, the center of rotation is usually near the waterline. The metacentre, based on your description, sounds like it would always be above the waterline.

 

[reterty]

I don’t think it is. When a ship heels, the center of rotation is usually near the waterline. The metacentre, based on your description, sounds like it would always be above the waterline.

Thank you. You are right