What is "surface of flotation"

Flotation \Flo*ta"tion\, n. [Cf. F. flottation a floating, flottaison water line, fr. flotter to float. See Flotilla.]

1. The act, process, or state of floating.

2. The science of floating bodies.

3. (Com. & Finance) Act of financing, or floating, a commercial venture or an issue of bonds, stock, or the like. Center of flotation. (Shipbuilding)

   1. The center of any given plane of flotation.

   2. More commonly, the middle of the length of the load water line.
      --Rankine.

      Plane of flotation, or Line of flotation, the plane or line in which the horizontal surface of a fluid cuts a body floating in it. See Bearing, n., 9

   3. .

      Surface of flotation (Shipbuilding), the imaginary surface which all the planes of flotation touch when a vessel rolls or pitches; the envelope of all such planes.