Measuring ships One can measure ships in terms of length overall, length between perpendiculars, length of the ship at the waterline, beam (breadth), depth (distance between the crown of the weather deck and the top of the keelson), draft (distance between the highest waterline and the bottom of the ship) and tonnage. A number of different tonnage definitions exist and are used when describing merchant ships for the purpose of tolls, taxation, etc.
measuring ships one can measure ships in terms of length overall length between perpendiculars length of the ship at the waterline beam (breadth) depth (distance between the crown of the weather deck and the top of the keelson) draft (distance between the highest waterline and the bottom of the ship) and tonnage a number of different tonnage definitions exist and are used when describing merchant ships for the purpose of tolls taxation etc