Chart Datum (CD) is a level set low enough to ensure that the tide rarely falls below it. The UK usually determines this as being approximately the level of Lowest Astronomical Tide. In effect, this is the minimum depth that can be achieved by a quayside or port entrance channel.
Length overall (LOA) means the maximum length of a vessel's hull when measured parallel to the waterline.
A ship’s beam refers to its width at the widest point, when measured at the ship's nominal waterline.
The draft of a ship's hull is the vertical distance between the waterline and the bottom of the hull (keel), which includes the thickness of the hull. The draft of a ship or boat signifies the minimum depth of water it can safely navigate.