The MD77ROT from MARINE DATA is a NMEA-based Rate of Turn Indicator, displaying the Rate in degrees per minute.


The MD77ROT from MARINE DATA is a NMEA-based Rate of Turn Indicator, displaying the Rate in degrees per minute. Housed in a robust, compact aluminium enclosure with a touch panel for background and pointer illumination, the MD77ROT is ideal for any vessel.

The MD77ROT provides a clear and easy to read 118 mm diameter analogue dial display graduated in 1 degree per minute rate increments. Rate range: Up to 30 degrees per minute to Port and Starboard.

Compact and rugged, the MD77ROT offers a solution for locations where the available space is limited and may be either bulkhead or panel mounted. Finished in jet black to complement other marine navigation equipment.

The MD77ROT from MARINE DATA: flexible in application, easy to install and simple to maintain.


  • Automatic warning of lost valid rate of turn data
  • Automatic detection of previously lost rate of turn data without a reset required
  • Local and Remote dimming control


  • To display Rate of Turn (ROT) data transmitted from NMEA 0183 compatible marine equipment at a convenient location


  • MD77ROT120 Version with 120°/min rate range
  • MD94DDU Data Distribution Unit
  • Rudder Angle Indicator System


  • Weight:1.25 kg (on bracket)
  • Dimensions: H 166 mm; W 200 mm; D 87 mm (on bracket) Fascia 144 x 144 mm; dial Ø 118 mm 140mm square panel cut-out
  • Mounting: Panel mounted or optional Bulkhead mounted
  • Connections: 1 x data cable to 15-pin D-sub plug
  • Construction: Aluminium alloy enclosure, Polycarbonate face RAL9005 Jet Black, fine texture
  • Finish: RAL9005 Jet Black, fine texture


  • Power Supply: 24 V dc (18-28 V); 6 W
  • Data Input: Digital RS422; NMEA 0183; 4800, 9600, 19200, 38000 Baud; auto-selecting
  • Data Sentences: NMEA 0183 ROT Rate of Turn Data
  • Outputs: External Alarm Loop (optional)
  • Cable: Supplied with 2.5 m multi-core data cable


  • Performance: ±0.5°/min accuracy; Alignment rate in excess of 40° per second
  • Illumination: Backlit white
  • Display: Rate of Turn, dial scale graduated in 1° per minute rate increments: full scale deflection 35o/min
  • Error Indication: Loss of Valid Data: Pointer assumes a vertical downward position and illumination flashes (alert condition)


  • IP rating: IP54
  • Operating temp: -15°C to +55°C
  • Storage temp: -25°C to +70°C
  • RoHS: Compliant
  • Magnetic: Magnetic Permeability: Category ‘A’
  • Compass: Safe Distance 100 cm


  • Complies with: IEC60945; IEC61162-1 (NMEA)
  • Type Approval: Germanischer Lloyd (GL)