The Marine Data MD73HR/W is a weatherproof, IP66-rated electromechanical tape-style NMEA compass heading repeater manufactured in the United Kingdom by Marine Data Systems. Derived from the standard MD73HR tape repeater, the “/W” variant is encased in a fully weather-sealed marine-grade aluminum housing designed for exposed bridge wing stations, open steering positions, flybridges, and naval deck installations.

The unit displays heading information using a smooth, high-contrast horizontal moving tape scale (viewing a 35° window of the compass card) behind a fixed lubber line, combined with a digital numeric display for instantaneous 0.1° resolution readouts. Driven by digital stepper motor control, the MD73HR/W processes standard NMEA 0183 serial heading sentences ($HDT, $HDG, $HDM, $THS) from gyrocompasses, satellite compasses, and magnetic sensors. Variable red LED illumination guarantees glare-free operations during night watches without impairing night-adapted vision.

Key Features:
• IP66 Weatherproof Enclosure: Sealed heavy-duty housing engineered for exposed deck stations, flybridge helms, and bridge wing bulkheads.
• Continuous Moving Tape Scale: High-contrast horizontal moving tape display provides smooth visual tracking of vessel heading changes.
• Dual Analog & Digital Presentation: Combines an electromechanical moving tape scale with a digital numeric readout for precision heading verification.
• Universal NMEA 0183 Interfacing: Decodes serial NMEA 0183 heading data ($HDT, $HDG, $HDM, $THS) with automatic baud rate detection.
• Variable Red Night Illumination: Dimmable red LED backlighting controlled locally via front rotary knob or remotely via NMEA commands.