The Marine Data MD77ROT is a high-precision analog dial Rate of Turn (ROT) indicator manufactured in the United Kingdom by Marine Data Systems. Specifically engineered for commercial vessels, naval ships, and tugboats requiring precise turning rate feedback during docking, pilotage, and river navigation, the MD77ROT decodes digital NMEA 0183 sentences ($ROT or $ROTA) from shipboard gyrocompasses, rate gyros, or AIS systems.

The instrument features a high-contrast center-zero analog pointer scale (typically calibrated for ±30°/min or ±300°/min full scale) allowing instant visual assessment of Port and Starboard angular turning speeds. Housed in a robust marine-grade aluminum alloy enclosure, the unit includes dimmable red LED backlighting for clear visibility during nocturnal watchkeeping on the wheelhouse console or main steering stand.

Key Features:
• Clear Center-Zero Dial: High-visibility analog pointer presentation for immediate indication of Port and Starboard vessel rate of turn.
• Universal NMEA 0183 Compatibility: Automatically decodes standard serial NMEA 0183 data ($ROT, $ROTA) across standard marine baud rates.
• Variable Red Night Illumination: Fully dimmable red LED dial lighting controlled via local rotary knob or remote NMEA serial commands.
• Flexible Scale Calibration: Supports standard commercial scales (e.g., 30°/min, 60°/min, or 300°/min) matching vessel maneuverability requirements.
• Marine Class Rugged Build: Corrosion-resistant aluminum alloy chassis engineered to satisfy IEC 60945 environmental and EMC standards for bridge instrumentation.