Which statement correctly identifies propeller currents?

• A. Suction current is forward of the propeller; Discharge current provides wash over rudder
• B. Suction current is behind the propeller; Discharge current provides wash over bow
• C. Suction current is above water; Discharge current is below water
• D. Suction current is for speed; Discharge current is for depth

Answer: (A)

Propeller currents come in two zones: a suction current on the forward side of the propeller where the pressure is lower and water is drawn toward the blade, and a discharge current on the aft side where water is pushed away, creating a high-velocity jet that flows aft along the hull and washes over the rudder. The suction current being forward of the propeller and the discharge current providing wash over the rudder aligns with how the rotating blades create a low-pressure region in front and a high-pressure jet behind. This jet enhances the flow past the rudder, aiding steering. The other statements misplace these flows or assign effects (like wash over the bow or tying suction to speed/depth) that don’t fit how propeller-induced water movement actually works.