On hardware and sensors in detail:

As an introduction, many sensors (compass, speed, depth, temperature, wind) are now available as stand-alone NMEA devices, thus eliminating the need to make their readings visible on a display before their data is transmitted to other NMEA-listeners. This is major step ahead to develop custom-made systems for a yacht with little or no dedicated displays, which seems to become the future of these systems. However not all units available allow the calibration on the sensor itself, which should be a built-in feature on all units.

Heading/Compass Sensor (Aimar H2183). This unit sends data at high frequency (10 Hz), it may be calibrated and zero-ed to north with two simple buttons on the unit itself making it compatible to lot of other units and displays.

ACTISENSE NDC-4 Multiplexer:

The NDC-4 shares a number of highly useful features:
  • It delivers one single NMEA data set, useful when existing displays lack the capability to receive more than one data set/have only one gate.
  • It may integrate up to 5 NMEA talkers (but only 4 are used in our system)
  • It converts incoming NMEA 0183 data to NMEA V2.0 data by adding necessary NMEA checksums. This allows operation of the latest software packages. (Note, modern packages and apps for the iphone etc may not accept NMEA 0183 data < V2.0)
  • It allows to suppress redundant NMEA phrases, commonly sent by many NMEA talkers, which removes clutter and redundant information on the system and improves system speed
  • It allows for prioritization of NMEA talkers thus eliminating in part differences in transmission frequency of NMEA talkers installed
  • It allows to increase output speed from 4.800 up to 115 k baud thus it may integrate AIS data at 38.400 (Hi-speed NMEA 0183) baud easily.
  • It provides perfect opto-couplers to take away any electrical issues caused in the past by equipment not completely not programmed to the NMEA 0183 standard.


Following a number of problems with the listeners onboard due to their different age and standards designed we decided to install this unit as it will insulate all listeners against eachother galvanically.

WIND Unit RO LCJ Capteurs Ultrasonic Sensor). These units are sturdy, motionless devices which show excellent linearity, probably better than any other mechanical device. Please note LCJ Capteurs now manufacture the CV7-V a unit better suited for sailing yachts. In addition these units are available without cable facilitating installation on mast-tops. They can be networked to most systems on the market and those of the past. Unfortunately they cannot be zero-ed on the unit/its little blackbox itself. The old unit sends at a low frequency (1 Hz), their most modern unit send at 3 Hz, super units may send with up to 10 or more Hz, which should be the standard for good AP performance.

AIS Amex Widerling B600S .This particular model comes with separate GPS antenna, a built-in antenna switch (no secondary aerial needed), all cables required and delivers data from NMEA0183 and NMEA 2000 connectors. The USB port should not be used for continuous operation but for programming only.

CETREK Depth Sensor incl. interface* (#930-379). This sensing equipment was made for high precision as it will tune its frequency to depth detected, ie frequency will increase in shallow waters increasing overall precision.

CETREK Speed/Temp Unit (AIRMAR ST850)

Garmin GPS 120*, a simple but now old 8-satellite GPS.

Move on to what displays are used in the system

* CETREK NET devices are out of production, so is the Garmin 120 GPS. We have some documentation like manuals for the units listed as well as on some CETREK 2000 models. Parts for these units and repairs may be available from The Servicecentre This company will do repairs on nearly all marine electronics.