Enebakkveien 150, RYEN , 0680 OSLO +47 23 30 22 70 sales@skipper.no

Navigation Speed Logs

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

  • 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)

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.


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
- 28x30 pixle alphanumeric LEDs (red) with dimming
- Multi - Panel PC 9" touch display, resolution 800x480
Mounting dimensions display:
- Dot matrix display: 124x124 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)
  • IMO Wheelmarked
  • MED-B
Available in most major harbours, world-wide through extensive dealer network

Downloads available

One full system consist of:

SD21-SB Touch display
CD402CU-SC Dot Matrix display for STW
Sensor options:
Needed: SL-SN300-SA Satlog GPS and Glonass antenna
One of the below sensors are needed:
DL1SG-SA for 60 mm Sea Valve
DL1ST-SA for Steel Tank
DL1STA-SA for Aluminium Tank
DL1SDB-SA for 100 mm Sea Valve
DL1SN-SA for Simrad NL-Log retrofit
DL1SS-SA for Sagem/Safran retrofit
DL1SV-SA for Naviknot SRD331 retrofit
DL1SX-SA for PCSV60 retrofit
Electronic Unit:
Bottom housings:
SB-60-SA Sea Valve for double bottom 
DB-60-SA Sea Valve for single bottom
ETNSTCL Steel Tank
ETNALC Aluminium Tank