The stem.
The bottom of the boat is called the keel. Attached to and atop that is the hull, part of which is below the waterline, part above. Unless you're talking about a little ol' flat bottomed dinghy -- then the bottom is just called the bottom.
Continent shelf
The flat part of your elbow is called the olecranon.
It is round but as a flat part at the bottom
plumage
whatis the flat part of the seafloor called?
The top part of a wave is called the crest, while the bottom part is called the trough.
A flat piece of glass. Also, any lens where the shape of the convex part matches the shape of the concave part. An example would be a flat piece of glass bent over a sphere.
yes, it can. if you realisee, the cone has a bottom part, opposite to its tip, it is flat.
A flask. See http://www.indigo.com/glass/gphglass/volumetric-flask.html
The bottom part of a cake is called the base.
Firstly, the Earth is round, so the ocean cannot be flat. Secondly, the Sun and the Moon's gravity are pulling on the ocean surface, causing it to bulge. Thirdly, there are waves and currents in the ocean.