A mechanical sensor that correctly measures wind and works with your installation does not need replacing simply because an ultrasonic model exists. For a new project, first compare the location, useful data, and integration with the onboard system. Technology comes next: ultrasonic sensors include time-of-flight and acoustic resonance used by FT Technologies. These are not two names for the same principle.
This guide helps you choose an approach. It is neither a comparative sea trial nor a validation of your boat’s wiring.
The essentials in 30 seconds
- Keep a satisfactory mechanical sensor if its condition, parts, and integration still meet the requirement.
- “Ultrasonic” does not always mean “time-of-flight”: FT uses Acu-Res acoustic resonance.
- Lack of moving parts does not exempt you from checking mounting, connections, and sensor condition.
- An electrical interface, a data protocol, and compatibility with a display are three separate checks.
- To choose, start from the exact reference of the sensor and of the processor, not from a universal ranking of technologies.
Table of contents
What problem are you trying to solve?
Before comparing sensors, describe the problem: missing wind speed, unstable direction, interrupted data, damaged part, or need to integrate into a new electronic suite. These are not the same decisions.
Missing data alone does not prove that the sensor is faulty. Power supply, cable, connectors, and configuration are part of the diagnosis. Buying a new device without identifying the cause may leave the problem intact.
If the installation works, keeping the existing setup is a valid option. Check its manual, the condition of components, and the availability of spare parts. Replacement is justified only by an identified need or failure, not by the “new technology” label.
Mechanical, time-of-flight, resonance: three principles to distinguish
A mechanical assembly uses moving parts: cups or a propeller for speed, a vane anemometer for direction. An ultrasonic sensor measures using sound waves, without these moving measuring parts.
In a time-of-flight approach, wind alters the propagation time of sound between transducers. With FT, the Acu-Res method exploits phase variations of a wave in resonance within a cavity. Acoustic resonance therefore belongs to the ultrasonic family. FT manufacturer explanation, January 2026.
| Approach | What performs the measurement | What to check before choosing |
|---|---|---|
| Mechanical | Moving parts for speed and direction | Mechanical condition, replacement parts, existing manual and integration |
| Time-of-flight ultrasonic | Sound propagation between transducers | Sensor geometry, measurement conditions, manual and interface for the exact model |
| Acoustic resonance ultrasonic | Wave resonance in a cavity | Exact FT variant, manufacturer conditions, mounting and output configuration |
This table describes principles, not a ranking of precision. To compare performance, you must evaluate models, test conditions, and processing chain. A single technology does not determine the quality of the measurement obtained on board.
What matters in a sailboat installation
Placement and direction reference
The sensor measures where it is installed. Have its location, nearby obstacles, and the orientation of its direction reference checked against the manual. Switching technology does not automatically correct the installation.
For a program where wind data serves for steering or performance analysis, also specify the expected system outputs: local measurement, apparent wind, calculated wind, magnetic reference, or other. Do not assume that a sensor with a compass or heel sensor performs all boat corrections.
Interface, protocol, system: three different levels
RS422, RS485, and CAN describe communication interfaces. NMEA 0183 and NMEA 2000 describe data exchanges. The presence of an interface alone does not guarantee that the display or computer accepts the messages, mode, or configuration chosen.
Concrete example: the FT602-D-SM manual, revision A01, describes NMEA 2000 over CAN and its configuration (§7 and §8.3.10). This establishes a function of the documented model, not a validation of all FT602 packs connecting to all onboard networks.
Before purchase, jointly verify the reference, hardware version, received data, power supply, connectors, and cable. Our NMEA 2000 network architecture guide explains the network context; it does not replace the sensor manual.
No moving parts does not mean no maintenance
Do not replace "mechanical maintenance" with "zero maintenance." For example, the FT742 analog manual requires inspection of the body, seals, fasteners, and cable, along with cleaning per its instructions (§4.1). This is a requirement of this model, not to be blindly copied to others. FT742-A-DM manufacturer manual, 9000322 Rev A.01.
Which references should you examine?
For a multi-brand comparison, start with the sailboat anemometer comparison tool and the datasheets of the selected references.
| Your search criteria | Useful starting point | What remains to be verified |
|---|---|---|
| Keep an existing mechanical unit | Its reference and datasheet | Diagnosis, condition, parts and existing system |
| Examine the FT range with acoustic resonance | FT Technologies collection, FT602-D-SM-EV, FT743-D-SM kit 1.5 m | Base model, configuration, mounting and pack contents |
| Examine an LCJ solution | CV3F, CV7-BARO | Exact variant, available data and interface as per its datasheet |
These links are selection starting points, not a list of direct equivalents. The guide does not state that a CV3F, a CV7-BARO and an FT can substitute for one another without modification.
Mistakes to avoid
- Choosing based on stated precision without checking the wind speed, orientation and conditions under which it is specified.
- Confusing output rate with data quality after filtering and processing by the system.
- Applying the outputs of a single variant to an entire product line.
- Assuming that a similar cable or connector shape proves compatibility.
- Assuming that an integrated compass provides full motion compensation.
- Buying an assembly marketed as a "kit" without verifying its contents and what else is required.
Our situation-based recommendation
If your existing mechanical unit works and meets the requirements, keep it. Document its maintenance and parts rather than replacing it without an identified benefit.
If you are upgrading the electronics: qualify the entire system before the brand. Note the references of the sensor, processor and displays, then verify the interface, messages and accessories. FT and LCJ should be examined without being presented as direct replacements.
If you need a measurement for a demanding project: request proof for the exact model. Compare specifications under the same conditions, plan acceptance tests and validate the architecture. This guide does not designate a universal winner for racing or offshore sailing.
The next useful step is a short list: current reference, symptom or objective, receiving devices, interface, mounting and available documentation. You can then compare anemometers in the catalog without conflating the sensor choice with the choice of the complete system.
Sources and next reading
Sources verified on 16 October 2026: FT principles, January 2026, FT602-D-SM 9000937 manual Rev A01, August 2026, §2.1, §7 and §8.3.10, FT742 analog 9000322 manual Rev A.01, June 2023, §4.1. The 2023 manual is a technical document maintained in the folder, not a commercial update.
Also read: FT Technologies range, multi-brand wind transducer comparison, NMEA 2000 architecture.
Commercial transparency. Skysat markets FT Technologies and LCJ Capteurs products among others. This guide relies on the cited documentation; it makes no claim to Skysat comparative testing or commercial independence.
