Vessel rides on a cushion of air. Lighter weight, higher speeds, smaller load capacity.

Supported by moving water. At slower speeds, they are hydrostatically supported

Displacement Ships Float by displacing their own weight in water. The Ship is supported by its buoyancy. (Archimedes Principle)

Hydrodynamics pressure developed on the hull at high speeds to support the vessel. Limited loads, high power requirements.

Supported by underwater foils, like wings on an aircraft. Dangerous in heavy seas. No longer used by USN.

An object partially or fully submerged in a fluid will experience a resultant vertical force equal in magnitude to the weight of the volume of fluid displaced by the object.

Intersection of planes (waterlines) parallel to the baseline (keel).

Intersection of planes (buttock lines) parallel to the centerline plane

Intersection of planes to define section line - Sectional lines show the true shape of the hull form - Forward sections from amidships : R.H.S. - Aft sections from amid ship : L.H.S.

Overall length of the vessel

Water line where the ship is designed to float

parallel planes from forward to aft, evenly spaced (like bread).Normally an odd number to ensure an even number of blocks.

imaginary vertical line where the bow intersects the DWL

imaginary vertical line located at either the rudder stock or intersection of the stern with DWL

horizontal distance from FP and AP

the point midway between FP and AP ( ) Midships Station

longitudinal curvature given to deck

vertical distance measured from keel to deck taken at amidships and deck edge in case the ship is cambered on the deck

vertical distance from keel to the water surface

transverse distance measured amidships

transverse distance across the each section

transverse curvature given to deck

locate the bottom of the ship

distance from depth to draft (reserve buoyancy)

opposite of flare

outward curvature of ship’s hull surface above the waterline