How do vertical-axis propellers help tugboats maneuver?

Vertical-axis propellers, also known as rotating-blade propellers, significantly enhance the maneuverability of tugboats by allowing the operator to vary both the magnitude and the direction of thrust at will.1

Unlike traditional screw propellers that rely on a rudder to change the direction of the vessel, these systems provide exceptional versatility by enabling the tugboat to exert a pull equally well in any direction. This capability allows tugs to maneuver with great ease, including the ability to turn the ship around almost on its own center. Because these propellers can adjust the direction of their thrust instantaneously, they are considered more versatile than any combination of a standard screw propeller and a rudder, making them ideal for the high-thrust, low-speed demands required during towing operations.12