SKIPPER SD21 Speed over ground (SOG) Speed log with built in STW sensor

(the price includes VAT)

The SKIPPER SD21 is a Single Axis Doppler Speed Log and a Dual Axis SATLOG Combined. It is designed to meet the IMO resolution MSC334(90) that require two separate speed logs for vessels above 50 000 dwt. The SKIPPER SD21 gives accurate navigation parameters, measured as they happen, and presented in a logical, user friendly way.

SKU: sd21 Category:


  • IMO Wheelmarked with MED-B
  • Speed over ground (SOG) in three axis (Docking mode)
  • Doppler Speed through water (STW) in one axis
  • Sea Temperature readout from sensor
  • NMEA 0183 output
  • LAN output
  • GPS, Glonas (SOG) and Doppler speed log (STW)


Speed Log:


Number of Axis:


Speed range longitudinal:

+/- 99.9 knots from Satlog

+/- 50 knots from doppler speed log

Speed range transversal:

+/- 99.9 from Satlog

N/A from doppler

Water track (from):

2 meter

Temperature accuracy error:


Power Supply:

AC:115-230 V 50/60 Hz

DC: 20-32 V

Power Consumption:

– Display 5W

– Elecronic unit 10W


– 28×30 pixle alphanumeric LEDs (red) with dimming

– Multi – Panel PC 9″ touch display, resolution 800×480

Mounting dimensions display:

– Dot matrix display: 124×124 mm. Bracket or panel mounting

– Touch display: 224.5 mm wide x 140 mm high

– Antenna: 100 mm height, 180 mm width and 790 mm long

IP rating:

Display: 2x

Antenna: 66


<0.2 knots or 2% whatever is greater


1.2 kgs for Graphic display

1.8 kgs for dot matrix display for STW

3 kgs for antenna

4 kgs for electronic unit

Standard cable length:

Not included for the antenna. Needed cable is 4 TSP (Twisted, shielded pairs) minimum 0.5 mm2. Max length 100 m

40 m for the STW sensor

Mounting options:

  • 60 mm Sea Valve for single bottom
  • 60 mm Sea Valve for double bottom
  • Steel Tank
  • Aluminium tank
  • 100 mm Sea Valve for single bottom
  • 100 mm Sea Valve for double bottom
  • Simrad NL-Log retrofit
  • Sagem/Safran retrofit
  • Naviknot SRD331 retrofit
  • PCSV60 retrofit

Speed alarms:

  • High and low speed limits
  • Power failure
  • Sensor failure


  • 4xNMEA 0183
  • 2xLAN (IEC61192-450)


  • 2xNMEA 0183 (IEC61192-1)
  • 2xLAN (IEC61192-1)

NMEA Outputs:

  • Speed: VBW and VHW
  • Distance: VLW
  • Others: MTW (Temperature)
  • VTG: Actual course and speed relative to the ground
  • DDC: Dimming command output
  • GPS: Gyro and status
  • HDT: Actual vessel heading in degrees.
  • ROT: Rate of turn and direction of turn
  • THS: Actual vessel heading in degrees
  • GSA: Satellite DOP and active satellites
  • GSV: Number of satellites in view, satellite ID and evaluation
  • SNR: Position and time signals
  • GLL: Longitude and latitude of vessel position, time of position fix and status
  • Note: This system is a speed log and cannot be used as primary source of other types of information. Position, course over ground and heading is only to be used as secondary sources


  • IMO Wheelmarked
  • MED-B


Available in most major harbours, world-wide through extensive dealer network