The beam of a boat is the measured width of the broadest part of a vessel
Beam...the widest part of a boat
The definition of beam is the widest part of the boat
transom
Die
beam
a transom
The length is "stem to stern" or "bow to transom", and the width is "beam to beam".
At the widest point. Think of it this way; "what is the smallest door this boat could fit through?".
The beam is the width of the boat at its widest point. If something is 'on the beam' it is to the side of the boat. The more typical nautical expression for this is "abeam" for instance a buoy could be abeam the mast, ie if you drew a line between the buoy and the mast, it would be perpendicular with the line drawn between the front and back of the ship (bow and stern respectively)
I work for a marina, its called length waterline
This all depends on what type boat your are talking about. There are two factors that cause a boat to float shallow: the beam width and how light it is. The wider the beam the more efficient it is on spreading out the weight of the boat which makes it float shallower. With a 96in. on a 20ft. boat you should be able to float shallower than a foot probably around 7in, depending on how much gas is in the boat.
That is a boat hull that does not have a keel beam or a defined chine.