Question 355General Subjects - Assistant Engineer

The correct answer is D) The back of the propeller blade is the side of the blade which faces upstream during ahead motion and is the side of the blade known as the suction side. This is correct because the back of the propeller blade is the side that faces the oncoming flow of water as the propeller rotates, creating a region of low pressure or suction on that side of the blade. This suction side is what generates the thrust that propels the vessel forward. The other side of the blade, facing downstream, is known as the pressure side. The other options are incorrect because they either describe the wrong orientation of the blade relative to the direction of water flow, or incorrectly identify the suction and pressure sides of the propeller blade.