What results from a decrease in pressure between the ship and the bank due to the venturi effect?

• A. Bank Suction
• B. Set
• C. Drift
• D. Advance

Answer: (A)

The concept behind bank suction arises from the Venturi effect, which describes how a fluid's velocity increases as it flows through a constricted section of a pipe or channel, leading to a decrease in pressure. When a ship is navigating near a bank or shore, the water flow around the hull changes due to the limited space.

As the ship moves closer to the bank, the water between the ship's hull and the bank accelerates, which decreases the pressure in that narrow area. This lower pressure creates a suction effect on the ship towards the bank, a phenomenon known as bank suction. Essentially, the ship experiences a force pulling it towards the bank due to this pressure differential.

Understanding bank suction is crucial for the Officer of the Deck, as it can significantly impact the maneuverability and navigation of the vessel, especially in confined waters. Consequently, recognizing bank suction helps in anticipating how the ship will behave in proximity to the shoreline or other vessels.