The Marine Data MD74HR is a modern, high-precision digital NMEA heading repeater display manufactured in the United Kingdom by Marine Data Systems. Housed in a compact panel-mount enclosure, the MD74HR presents shipboard heading information through a clear dual-display interface combining a large 4-digit numeric readout with a graphic OLED moving tape-repeater display.

Capable of driving display outputs down to 0.1° heading resolution, the MD74HR automatically senses and decodes standard NMEA 0183 serial heading sentences ($HDT, $HDG, $HDM, $THS) from shipboard gyrocompasses, satellite compasses, and magnetic sensors. Built into a powder-coated marine-grade aluminum housing, the unit features full-range red OLED display dimming to preserve night vision during nocturnal watchkeeping on the vessel bridge.

Key Features:
• Dual OLED Graphic & Numeric Display: Combines a clear 4-digit numeric readout with a high-resolution moving tape compass card graphic.
• High-Accuracy 0.1° Heading Readout: Delivers real-time heading information with 0.1° resolution and instant response time.
• Universal NMEA 0183 Interfacing: Decodes serial NMEA 0183 data ($HDT, $HDG, $HDM, $THS) with automatic baud rate selection.
• Variable Red OLED Night Illumination: Dimmable red OLED lighting controlled locally via front pushbuttons or remotely via NMEA commands.
• Compact Panel Cutout Footprint: Designed for flush mounting in wheelhouse control consoles, overhead instrument panels, and steering stations.