Marine wind sensors measure one of the most important environmental forces acting on a vessel: wind speed and wind direction. But a traditional mechanical cup-and-vane anemometer and a modern ultrasonic sensor obtain those measurements in fundamentally different ways.
Imagine a vessel running through an unsettled night sea. The bridge windows are dark, the deck is wet and the wind has begun to shift.
On the display, two figures change: wind speed and wind direction.
They look simple. But before those numbers appear on the bridge, a sensor exposed above the vessel has had to measure moving air, process that measurement and send usable data into the ship’s system.
That is where the difference between mechanical and ultrasonic marine wind sensors becomes important.
A traditional mechanical anemometer can use rotating cups to measure wind speed and a separate vane to measure direction. An ultrasonic anemometer removes those moving measuring components and instead determines wind using ultrasonic signals between transducers.
When comparing marine wind sensors, construction, environmental conditions, data interfaces, mounting position and approval requirements can all affect which product is suitable.
This guide uses the Gill WindSonic, Gill WindObserver II and Gill IS WindObserver as examples of different ultrasonic products designed for different operating requirements.
How Marine Wind Sensors Measure Speed and Direction
At the most basic level, marine wind sensors are used to obtain information about wind speed and wind direction.
How fast is the air moving?
Depending on the equipment and configuration, wind speed can be transmitted or displayed in units such as metres per second or knots.
Where is the wind coming from?
Wind direction is measured relative to the correctly aligned reference of the installed sensor.
The technology inside different marine wind sensors can be very different even when the final bridge display presents similar information.
but behind them is a complete chain of measurement, processing and data transmission.
Mechanical Marine Wind Sensors: The Traditional Cup-and-Vane Approach
Traditional mechanical marine wind sensors are visually easy to understand because the measuring components can be seen moving.
The cup assembly rotates in the airflow and that rotation is used to determine wind speed. A direction vane rotates to align with the airflow and provides the directional measurement.
This does not mean every mechanical anemometer is unsuitable for marine use. It means its operating principle includes moving components such as rotating assemblies and bearings, and inspection or maintenance requirements depend on the specific instrument and operating environment.
Ultrasonic Marine Wind Sensors: Measurement Without Moving Measuring Parts
Ultrasonic marine wind sensors take a very different approach.
Gill’s WindObserver II measures how long an ultrasonic pulse takes to travel between opposing transducers and compares the travel time in the opposite direction.
If the airflow is moving along that measurement axis, the ultrasonic signal travelling with the airflow reaches the opposite transducer sooner than the signal travelling against it.
By comparing those transit times across its measurement axes, the sensor calculates wind speed and direction.
Ultrasonic travel time in one direction
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Compared with travel time in the opposite direction
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Airflow affects the transit-time difference
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Wind vector is calculated
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WIND SPEED + WIND DIRECTION
Modern ultrasonic marine wind sensors therefore obtain their wind measurement without the rotating cups and physical direction vane used by a traditional mechanical design.
Ultrasonic vs Mechanical Marine Wind Sensors
| Feature | Ultrasonic sensor | Mechanical cup-and-vane sensor |
|---|---|---|
| Measurement method | Ultrasonic transit-time measurement. | Physical rotation of cups and direction vane. |
| Moving measuring parts | No. | Yes. |
| Wind speed | Calculated from ultrasonic measurements. | Derived from cup rotation. |
| Wind direction | Calculated from measurements across the sensor axes. | Derived from physical vane position. |
| Interfaces | Product dependent. Gill models covered here include serial, NMEA and selected analogue interfaces. | Depends on the particular mechanical instrument and its associated electronics. |
| Mechanical wear points in the sensing mechanism | No rotating cup or vane bearings are required for measurement. | Moving assemblies inherently include mechanical components. |
Ultrasonic marine wind sensors still require appropriate positioning, alignment, wiring, power and a compatible data interface. A poorly positioned high-quality sensor can still be exposed to disturbed airflow.
Now imagine the same requirement on a smaller vessel. Space is limited. The sensor must sit high enough to see clean airflow, but the installation does not require the stainless-steel construction or specialised hazardous-area system of the larger industrial sensors.
This is where the WindSonic family becomes relevant.
Gill WindSonic Marine Wind Sensors
Gill’s WindSonic 60 is a compact ultrasonic wind speed and direction sensor with no moving parts.
Gill specifies a wind-speed range of 0–60 m/s (116 knots) and a wind-direction range of 0–360°.
The manufacturer lists applications including marine vessels, data buoys, ports, harbours and coastal monitoring stations.
Different WindSonic versions provide different output arrangements, so the correct part number matters when specifying marine wind sensors for integration with existing equipment.
Gill WindSonic 60 – Option 2
Black WindSonic 60 with RS232, RS422 and RS485 output options.
- Ultrasonic wind measurement.
- No moving measuring parts.
- 60 m/s specified measurement range.
- RS232, RS422 and RS485 on this specific listed version.
Need Analogue Output Too?
The WindSonic 60 Option 3 listing adds analogue output to RS232, RS422 and RS485.
Gill WindObserver II Marine Wind Sensors
Where more demanding environmental requirements apply, marine wind sensors may need a different level of construction and configuration.
Gill specifies 316 stainless-steel external construction, IP66 moisture protection and a wind-speed range of 0–65 m/s for WindObserver II.
The range includes unheated and heated versions and can be supplied with analogue outputs.
The supplied Gill documentation also identifies WindObserver II as Lloyd’s Register Type Approved.
Gill WindObserver II – Unheated
65 m/s, analogue version with 2 metre cable.
- 316 stainless-steel external construction.
- IP66 protection.
- 65 m/s specified measurement range.
- Analogue configuration.
Gill WindObserver II – Heated
65 m/s analogue version with standard heating and 2 metre cable.
Why Mounting Position Matters for Marine Wind Sensors
Selecting the correct unit is only part of specifying marine wind sensors.
Wind measurement depends on the airflow reaching the sensing head. Masts, superstructure and nearby equipment can disturb that airflow.
Gill therefore gives specific positioning guidance for its wind sensors.
Avoid unnecessary turbulence
The sensor should be positioned so surrounding vessel structures interfere with the airflow as little as practical.
Consider nearby transmitters
Radar and radio transmitting equipment also need to be considered when determining the installation position.
Gill advises avoiding installation in the plane of a radar scanner and specifies at least 2 metres vertical separation.
Its documented suggested all-round minimum separations include:
- VHF: 1 metre
- MF/HF: 5 metres
- Satcom: 5 metres, while considering the likely transmission path
These are Gill manufacturer installation recommendations for the relevant products, not universal spacing rules for every anemometer. Always follow the current manual for the exact unit being installed.
The sensor has measured the airflow. But nobody on the bridge wants to stand outside looking at the sensor.
The measurement now has to become useful information.
How Marine Wind Sensors Feed Data to the Bridge
Marine wind sensors are therefore normally part of a wider measurement and display system rather than isolated mast-top hardware.
Depending on model and configuration, Gill sensors can communicate using serial interfaces and, on selected versions, analogue outputs.
Gill’s WindObserver II documentation describes direct use with its WindDisplay. The documented Marine WindDisplay arrangement uses NMEA output at 4800 baud.
Gill wind sensor
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Compatible serial / NMEA data
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Wind display or compatible host equipment
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WIND SPEED + WIND DIRECTION FOR THE OPERATOR
Displaying Data From Marine Wind Sensors
F&C Marine lists Gill meteorological TFT displays in both 24 V DC and 110–240 V AC supply versions.
Gill TFT Display
Gill meteorological TFT display with 24 V DC supply.
Gill TFT Display
Gill meteorological TFT display with 110–240 V AC supply.
Marine Wind Sensors, NMEA 0183 and NMEA 2000
When marine wind sensors are being integrated into an existing vessel network, the data interface matters.
Our guide to NMEA 0183 vs NMEA 2000 explains the difference between the two systems.
If you are commissioning or fault-finding serial equipment, our guide to reading NMEA 0183 data goes a stage deeper.
We also cover practical wind and data-network fault finding in our marine electronics diagnostics guide .
Now move the same measurement problem onto a tanker or hazardous industrial installation.
Wind speed and direction are still required. But the environment has changed — and suddenly the words “marine grade” are not enough to define the requirement.
Hazardous-Area Marine Wind Sensors and Intrinsic Safety
Gill explicitly states that where an intrinsically safe device is required, the IS WindObserver must be used.
This is an important distinction when choosing marine wind sensors for tankers, offshore installations or other environments where hazardous-area certification forms part of the equipment specification.
The Gill IS WindObserver is specifically designed as an intrinsically safe ultrasonic anemometer.
The supplied Gill documentation identifies ATEX, UKCA and IECEx certification and states that the IS WindObserver anemometer can be used in Zones 0, 1 and 2.
The associated Gill power/communications interface is installed in the non-hazardous area in accordance with the manufacturer’s system installation requirements. The complete installation must therefore be considered as a system, not simply as an anemometer head.
Gill IS WindObserver System with PCI
Intrinsically safe WindObserver system supplied with the mains-voltage power communications interface.
Gill IS WindObserver – Anemometer Only
Anemometer-only configuration for correctly engineered IS WindObserver systems.
Specialist Marine Wind Sensors: Where WindObserver 70 Fits
Model numbers can make it tempting to assume that a higher number automatically means a better choice for every vessel.
That is not how marine wind sensors should be selected.
Gill’s WindObserver 70 documentation specifies a 0–70 m/s measurement range and the product is positioned for more extreme weather and specialist applications, including aviation.
It should therefore be selected because its specification fits the installation, rather than simply because 70 is a larger number than 65.
Gill WindObserver 70 – Enhanced Heated
70 m/s digital WindObserver with enhanced heating.
When Marine Wind Sensors Are Only Part of the Requirement
Sometimes the job is not simply to fit an anemometer.
A wider environmental monitoring installation may require additional meteorological parameters from an integrated weather station.
That is a different product category from dedicated marine wind sensors such as WindSonic or WindObserver.
F&C Marine has previously worked with Gill MaxiMet equipment, and our existing article covering MaxiMet GMX-500 wind equipment provides a real-world example from the wider Gill weather-monitoring range.
Which Marine Wind Sensors Suit Which Applications?
Selecting between marine wind sensors therefore requires more than comparing physical size, maximum wind speed or price.
| Application | Product family to investigate | Reason | F&C Marine link |
|---|---|---|---|
| General / compact marine wind measurement | Gill WindSonic | Compact ultrasonic sensing with no moving parts. Gill specifically lists marine vessels among WindSonic applications. | WindSonic 60 |
| Demanding commercial marine / offshore | Gill WindObserver II | 316 stainless-steel construction, IP66 protection, optional heating and 65 m/s measurement range. | WindObserver II |
| Heated WindObserver II requirement | Heated WindObserver II | WindObserver II configuration with standard heating. | Heated WindObserver II |
| Hazardous-area application requiring an IS sensor | Gill IS WindObserver | Purpose-designed intrinsically safe WindObserver system. | IS WindObserver System |
| Specialist 70 m/s / enhanced-heating requirement | WindObserver 70 | Specialist WindObserver model with 70 m/s measurement range. | WindObserver 70 |
5 Questions to Ask Before Choosing Marine Wind Sensors
What environment is it entering?
Small vessel, commercial ship, offshore installation, shore site or classified hazardous area?
What data interface does the receiving equipment need?
RS232, RS422, RS485, NMEA-compatible serial data, analogue output or another requirement?
Where can the sensor actually be mounted?
Consider clean airflow, radar, transmitting antennas, nearby structures and the cable route.
Does the location require intrinsically safe equipment?
If the answer is yes, a normal marine WindObserver must not simply be substituted for the IS WindObserver.
Do you need a wind sensor or a broader weather station?
WindSonic and WindObserver are dedicated wind-measurement families. A wider meteorological requirement may point toward a different integrated weather-station solution.
These questions help prevent marine wind sensors being selected simply because a unit looks suitable or has a higher headline specification.
Marine Wind Sensors: The Difference Is Hidden in the Measurement
From the operator’s chair, mechanical and ultrasonic marine wind sensors may eventually produce the same two pieces of information: wind speed and wind direction.
But the route to those figures is very different.
A mechanical system relies on physically moving measuring components. An ultrasonic system such as Gill WindSonic or WindObserver determines wind using ultrasonic transit-time measurement.
From there, the choice becomes application specific.
WindSonic offers a compact solution for many general wind-measurement applications. WindObserver II brings stainless-steel construction, higher environmental specification and heating options. If the location requires intrinsically safe equipment, Gill provides a dedicated IS WindObserver system.
Whatever technology is chosen, reliable marine wind sensors still depend on suitable mounting position, airflow, alignment, data interface, power, cabling and the correct approval requirements for the installation.
The end result is reliable wind information where the crew or system needs it.
Gill Manufacturer Resources for Marine Wind Sensors
When specifying or installing marine wind sensors, current manufacturer documentation should always take priority over general descriptions or older specifications.
Gill Wind Sensor Documentation
Gill’s technical downloads include product manuals, datasheets and other supporting documentation.
Gill Instruments
Manufacturer information covering Gill wind and meteorological instruments.
Marine Wind Sensors FAQs
What do marine wind sensors measure?
Marine wind sensors are used to measure wind speed and wind direction. The method used to obtain those measurements depends on the sensing technology.
What is the main difference between ultrasonic and mechanical anemometers?
A mechanical anemometer relies on physically moving measuring components such as rotating cups and a direction vane. An ultrasonic anemometer determines airflow using ultrasonic measurements between transducers and does not require those moving measuring components.
Does Gill WindSonic have moving parts?
Gill describes WindSonic as a solid-state ultrasonic wind sensor with no moving parts.
Is Gill WindSonic suitable for marine applications?
Yes. Gill lists marine vessels, data buoys, ports and harbours among typical WindSonic applications.
What is the WindSonic 60 wind-speed range?
Gill specifies 0–60 m/s, equivalent to 116 knots, for WindSonic 60.
Is WindObserver II intrinsically safe?
No. Gill states that if an intrinsically safe device is required, the IS WindObserver must be used.
Can marine wind sensors connect to a dedicated wind display?
Compatible sensors can be connected to suitable displays or host systems. Gill documents WindObserver II integration with its WindDisplay, including a documented marine arrangement using NMEA output at 4800 baud.
Where should marine wind sensors be mounted?
They should be positioned where airflow is as free as practical from turbulence while following the manufacturer’s guidance concerning surrounding structures, radar and radio transmitting equipment.
Should I choose WindSonic or WindObserver II?
That depends on the required construction, measurement range, environmental conditions, heating requirement, interfaces and approvals. The actual installation should determine the model rather than choosing purely by physical size or price.
Need Help Choosing Marine Wind Sensors?
Tell F&C Marine what vessel or site the sensor is going on, where it will be mounted, what equipment must receive the data and whether the installation has marine, offshore or hazardous-area requirements.
Technical note: Product specifications, available variants, interfaces, certifications and installation requirements can change. Always confirm the exact product configuration and current Gill manufacturer documentation for the specific vessel, site and hazardous-area classification before specifying or installing equipment.