Bulbous bow: purpose and importance

What is the purpose of a bulbous bow? Why some ships are designed with a bulbous bow while other are not?


The purpose of a bulbous bow is to reduce the drag and improve the efficiency of a ship by “modifying” the flow of water around the ship’s hull.
When a ship is moving through the water, the bow creates a wave pattern called the bow wave. The bow wave is created by the displacement of water by the ship’s hull, and it is a major source of drag on the ship. The bulbous bow is designed to change the shape of the bow wave and reduce the drag caused by it.

The bulbous bow works by generating a wave that is in phase with the bow wave, which helps to cancel it out. This results in a reduction of the wave-making resistance, which is the resistance caused by the bow wave.

Not all ships are designed with a bulbous bow. The decision of whether to include a bulbous bow or not depends on the ship design/type and the operational profile. Such a decision is usually taken after extensive model testing and numerical simulations.