NAC-3 High Current Course Computer. The NAC-3 Autopilot Computer is the brains behind your Simrad autopilot system. It contains the electronics needed to operate a hydraulic steering pump or mechanical drive unit. Type: Central autopilot computer that serves as the control hub for Simrad autopilot systems. Power handling: High current design to reliably drive steering actuators and related components. Compatibility: Supports hydraulic steering pumps or mechanical drive units within the autopilot setup. Interface: Interfaces with other autopilot components to coordinate steering commands and navigation data. By serving as the central hub for steering control, the NAC-3 ensures reliable autopilot operation with hydraulic or mechanical drives, enabling smoother course tracking and reduced manual workload during long passages.