The angle of list is the degree to which a
vessel heels (leans or tilts) to either
port
A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Ham ...
or
starboard
Port and starboard are nautical terms for watercraft and aircraft, referring respectively to the left and right sides of the vessel, when aboard and facing the bow (front).
Vessels with bilateral symmetry have left and right halves which are ...
at equilibrium—with no external forces acting upon it. If a listing ship goes beyond the point where a
righting moment will keep it afloat, it will
capsize
Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is upside down in the water. The act of recovering a vessel fro ...
and potentially sink.
Listing is caused by the off-centerline distribution of weight aboard due to uneven loading or to flooding.
By contrast,
roll
Roll or Rolls may refer to:
Movement about the longitudinal axis
* Roll angle (or roll rotation), one of the 3 angular degrees of freedom of any stiff body (for example a vehicle), describing motion about the longitudinal axis
** Roll (aviation), ...
is the dynamic movement from side to side caused by
waves
Waves most often refers to:
*Waves, oscillations accompanied by a transfer of energy that travel through space or mass.
*Wind waves, surface waves that occur on the free surface of bodies of water.
Waves may also refer to:
Music
*Waves (band) ...
.
See also
*
Angle of loll Angle of loll is the state of a ship that is unstable when upright (i.e. has a negative metacentric height) and therefore takes on an angle of heel to either port or starboard.
When a vessel has negative metacentric height (GM) ''i.e.'', is in unst ...
*
Heeling (sailing)
Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' (sailing ship, sailboat, raft, windsurfer, or kitesurfer), on ''ice'' (iceboat) or on ''land'' (land yacht) over a chosen cour ...
*
Capsizing
Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is upside down in the water. The act of recovering a vessel fr ...
*
Metacentric height
The metacentric height (GM) is a measurement of the initial static stability of a floating body. It is calculated as the distance between the centre of gravity of a ship and its metacentre. A larger metacentric height implies greater initial stab ...
*
Ship stability
Ship stability is an area of naval architecture and ship design that deals with how a ship behaves at sea, both in still water and in waves, whether intact or damaged. Stability calculations focus on centers of gravity, centers of buoyancy, the ...
*
Ship motions
Ship motions are defined by the six degrees of freedom that a ship, boat or any other craft can experience.
Reference axes
The '' vertical/Z axis'', or ''yaw axis'', is an imaginary line running vertically through the ship and through its ...
References
{{Ship measurements
Engineering concepts
Naval architecture
Ship measurements