SAMS Vessel Stability and Naval Architecture

Question 1

What does metacentric height (GM) measure in vessel stability?

Accepted Answer

The vertical distance from the center of gravity to the metacenter

Answer

GM is the vertical distance from the center of gravity (G) to the metacenter (M) and is the primary indicator of a vessel's initial transverse stability.

Question 2

A vessel with a negative GM will:

Accepted Answer

List permanently to one side and risk capsizing

Answer

A negative GM means G is above M, making the vessel unstable; it will heel to one side (angle of loll) and may capsize if the condition is not corrected.

Question 3

The center of buoyancy (B) is located at:

Accepted Answer

The centroid of the underwater displaced volume of the vessel

Answer

The center of buoyancy is the centroid of the displaced water volume—the geometric center of the submerged portion of the hull—where the buoyant force acts upward.

Question 4

Freeboard is defined as:

Accepted Answer

The vertical distance from the waterline to the upper deck edge

Answer

Freeboard is the vertical distance from the waterline to the freeboard deck edge, and its minimum value is regulated by international load line conventions to ensure reserve buoyancy.

Question 5

The righting lever (GZ) in a stability analysis represents:

Accepted Answer

The horizontal distance between vertical lines through G and B when the vessel is heeled

Answer

GZ is the horizontal (perpendicular) distance between the vertical line through G and the vertical line through B at a given angle of heel, representing the righting arm per unit displacement.

(SAMS) Society of Accredited Marine Surveyors Certified Practice Test

(SAMS) Society of Accredited Marine Surveyors Certified Practice Test

SAMS Vessel Stability and Naval Architecture