What is the primary advantage of transverse bow and stern tunnel thrusters when installed on ships?

Correct Answer: Option B — They provide increased maneuverability at low ship speeds.

Tunnel thrusters provide lateral force independent of the vessel's forward speed. This capability is essential for low-speed maneuvering, such as berthing or navigating restricted channels, where the main propulsion and rudder are ineffective due to insufficient water flow over the control surfaces.