A motor boat is measured along its centerline from the outside of the hull aft to the outside of the hull forward. This measurement does not include any attachments such as swim platforms, outboard motors, bow sprits, etc. This measurement is called the length overall (LOA). You may also hear the term length of waterline or load waterline (LWL). This is the length of the boat, parallel to its centerline, at the line where it meets the water.