The Sertan Lines on the Side of a Ship

The side of a ship is basically covered in grafite for the various things that you need to know. There'll be signs that will show you and how far the ship can dip as a result of the weight that it's carrying. Sometimes boats have this little protrusion at the bottom of the ship at the front, which you would never see. Thea, i think that's to stop the waves from, is it to help it ero dynamically o somyes, to break ackrate the waves somehow.