Bank cushion when a vessel travels close and parallel to a bank or seawall tends to:

• A. Forces the bow out, and pulls the stern in
• B. Forces the stern out, and pulls the bow in
• C. Has no effect on vessel direction
• D. Increases vessel draft

Answer: (A)

Bank cushion happens when a vessel passes very close to a bank or seawall and water is squeezed through a narrow gap between hull and bank. That restricted flow changes the pressure around the hull, creating a turning moment. The side near the bank tends to push the stern toward the bank, while the outer side pushes the bow outward, away from the bank. So the effect is a tendency for the bow to swing out and the stern to swing in toward the bank. This lateral influence is not about moving straight ahead, nor does it relate to draft changes.