Why do ships have a ‘’bulbous bow”?

The Bulbous bow (bulb) modifies the way the water flow around the hull, reducing drag and thus increasing speed, range and fuel efficiency. Large ships with bulbous bows generally have 12% to 15% better fuel efficiency than similar vessels without a bulbous bow. A bulbous bow also increases the buoyancy of the forward part and reduces the pitching of the ship a bit.