The essential in 30 seconds
- Coastal cruising + harbor manoeuvres: mechanical B&G 213 (€1,040, masthead unit only — spar and mast cable extra, ~+€1,050, display not included) or wireless entry-level ultrasonic Triton² wireless pack (€1,499, sensor + 2 displays + N2K interface) is enough. Caution: the first line is a bare component, the second is a complete pack — see price details below.
- Offshore cruising + transatlantic: vertical ultrasonic B&G WS710 (€2,043) or WS720 1.1m (€2,605). No bearings to wear, maximum salt/UV resistance, 10+ year reliability.
- Offshore racing: high-frequency 3D ultrasonic — B&G WS730S Ocean spec 1.4m (€3,080) or NKE 3D (NKE order after Skysat catalog reactivation). 10-20 Hz sampling, heel/heading compensation, essential for racing target optimization.
- Wireless or wired? Wireless (WS320) = 1 h installation, but battery replaceable annually. Wired (WS310/WS710/WS720) = 4-6 h installation (mast cable run), but long-term reliability and stable N2K power.
- Workshop verdict: 60% of our 30-50 ft sailboat installs are B&G WS320 wireless (cruising) or WS710/720 wired (comfort cruising). 100% of offshore racing installs are 3D ultrasonic, brand depends on existing processor ecosystem.
The sailboat anemometer is the instrument that feeds the entire decision chain in sail navigation: autopilot compensation in wind mode, VMG calculation, polars, heading optimization. An imprecise or delayed measurement propagates errors to all downstream indicators. This is why racing sailboats invest €3,000-5,000 in an Ocean spec sensor, while a cruising boat can settle for a €1,000 mechanical sensor.
This article distinguishes the two main technical families, presents the brands distributed by Skysat, and provides a workshop verdict by program. For NMEA 2000 cabling of a wind sensor, see our article NMEA 2000 backbone, drops, terminators.
Why the anemometer matters (more than you think)
Three technical uses make the wind sensor strategic:
- Autopilot in wind mode. The autopilot follows an apparent or true wind angle (close-hauled, beam reach, broad reach). If the sensor is 2 seconds late or measures imprecisely by ±5°, the autopilot will oscillate constantly — unnecessary fatigue + VMG loss + risk in rough seas.
- Polars and performance. The racing boat knows its polars (target speed based on true wind and angle). Without a precise and fast sensor, it is impossible to compare real-time performance with the theoretical target. This is what separates a high-performance crew from a crew that "does what it can".
- Sail and trim choices. Decisions on mainsail/genoa, jib/code zero, spinnaker/gennaker depend on true wind speed and angle. A ±2 knot measurement kills the optimal choice — especially in wind transitions (12-15 knot zone where you choose between J1 and J2 on IRC).
Mechanical anemometer — operation, brands, limits
Historical technology, present on pleasure sailboats since the 1970s. A cone of cups spins with the wind (speed), a vane orients into the wind (direction). Two analog sensors send signals to the onboard electronics.
B&G 213 — the cruising mechanical reference
Caution: the B&G 213 masthead unit (€1,040) is the head only. For a fully functional sensor, you must add the 213 standard spar (€480) and the 50 m mast cable (€570) — i.e. ~+€1,050, and the display is extra. Designed for B&G H5000 and Triton² systems. Accuracy ±1°, speed up to 60 knots, NMEA 0183 output or dedicated 213 interface. Compared to a turnkey pack (e.g. Triton² WS320), it ends up with a similar installed sensor budget, but with a mechanical vane.
- Advantages: robust (used for 30 years in ocean racing), controlled price, immediate readability (vane visible from the deck).
- Limits: bearings to wear (3-5 year lifespan in sustained sailing), accuracy drops in strong winds due to mechanical turbulence, does not measure the vertical component (rotation on deck due to swell).
- For whom: 30-45 ft cruising sailboat, coastal or offshore program without racing.
Available spare parts
- WS300/700 vane spare (€48)
- Speed cups (€31)
- Wind angle bearing WS300/WS700 (€83)
- WS300 speed bearing (€92)
The fact that B&G still sells spare parts shows the real longevity of well-maintained mechanical sensors — 10-15 years with overhaul every 3-5 years.
Ultrasonic anemometer — operation, brands, advantages
No moving parts. The sensor emits ultrasonic pulses between 2 or 3 pairs of transducers (depending on 2D vertical or 3D). Wind shifts the propagation of the waves — calculating the time of flight gives wind speed and direction.
B&G WS320 wireless (entry level)
The Triton² wireless WS320 pack (€1,499) is, unlike the 213, a complete pack: wireless sensor + 2 Triton² displays + N2K interface, ready to sail. This is our reference for retrofitting 30-40 ft sailboats that do not want to run a cable through the mast. If you already have Triton² displays, the WS320 sensor + N2K interface alone (€449) is enough. Battery replaceable annually (WS320 battery = €22).
B&G WS310/WS710 wired (comfort cruising)
The Triton² wired WS310 pack (€2,028) and the WS710 vertical 0.8 m (€2,043) add the reliability of wired (no battery) and long-term stability. The WS710 is the workshop reference for 35-50 ft offshore cruising sailboats.
B&G WS720/WS720S/WS730S (ocean racing)
The Ocean spec range — WS720 1.1m (€2,605), WS720S Ocean 1.05m (€2,865), WS730S Ocean 1.4m (€3,080) — is designed for offshore racing: optimized accuracy, high-frequency sampling, native integration with B&G H5000 processors (Hydra €1,139 or Performance €2,899).
NKE Marine Electronics — the French racing standard
The NKE system equips the majority of French offshore racing sailboats (IMOCA, Class40, Mini, Figaro). The NKE 3D anemometer measures the vertical component of the wind (useful in swell to avoid false autopilot corrections). Skysat NKE catalog is being reactivated — contact us for racing project quotes.
Calypso (compact ultrasonic)
Spanish brand specializing in compact and standalone solar ultrasonic sensors. Very popular on charter boats and light renovations. Not currently distributed by Skysat, but an interesting option for specific uses.
3D and lidar — where we stand in 2026
Truly 3D sensors measure the 3 components of the wind (fore/aft, port/starboard, up/down). The WS720S and WS730S do this, as do the NKE 3D. This is useful in rough seas where the boat moves on 3 axes — without the vertical component, the autopilot can interpret swell as a wind change and correct unnecessarily.
Lidar sensors (optical measurement by laser interferometry) remain confined to the world of high-level professional racing (America’s Cup, IMOCA front runners). They are not sold in the pleasure market in 2026 — their interest in cruising remains marginal vs. their price (€10,000-30,000 per unit).
Technical comparison table of main models
2026 distributor prices in France. Unless stated "pack", these are sensor only prices (display and interface sold separately). For the B&G 213, the €1,040 price is for the masthead unit only: plan for spar (€480) + mast cable (€570) for an installed sensor, i.e. ~+€1,050. The "Display included" line follows the convention of our anemometer comparison.
| Model | Technology | Measurements | Sampling rate | Wireless | Angle accuracy | Sensor price HT |
|---|---|---|---|---|---|---|
| B&G 213 | Mechanical | Speed + heading (2D) | 2 Hz | No | ±1° | €1,040 (head only, + spar/cable ~€1,050) |
| Display included | No (sensor only) | Yes in Triton² pack (€1,499) | No (sensor only) | No (sensor only) | No (sensor only) | No (sensor only) |
| B&G WS320 | Ultrasonic 2D | Speed + heading | 1 Hz | Yes (radio) | ±2° | €449 sensor only (or Triton² pack €1,499, displays included) |
| B&G WS710 0.8 m | Ultrasonic 2D | Speed + heading | 5 Hz | No (wired) | ±1° | €2,043 |
| B&G WS720 1.1 m | Ultrasonic 2D | Speed + heading | 10 Hz | No | ±0.5° | €2,605 |
| B&G WS720S Ocean | Ultrasonic 3D | 3D + temp | 10 Hz | No | ±0.3° | €2,865 |
| B&G WS730S Ocean | Ultrasonic 3D | 3D + temp + air pressure | 20 Hz | No | ±0.3° | €3,080 |
| NKE 3D HR II | Ultrasonic 3D | 3D + temp | 10 Hz | No | ±0.3° | ~€2,800 (on request) |
Wireless vs wired: selection criteria
Wireless (WS320) — when it makes sense
- Retrofit on sailboats where no cable has been run through the mast (common on 8-10 m older boats).
- Charter boats where battery life is not an operator problem (annual replacement included in warranty).
- Limited installation budget: 1-2 h vs 4-6 h for wired with mast cable run.
- No need for sampling rate > 1 Hz.
Wired (WS310, WS710, WS720, WS730, NKE) — when it is mandatory
- Offshore racing where 5-20 Hz sampling is required for wind steering.
- Offshore cruising where replacing a wireless battery is not feasible at sea.
- 45+ ft sailboats where cabling already exists (mast cable run standard on new boats ≥2010).
- Need for accuracy <1° angle and <0.5 knot speed.
Examples by program: coastal cruising → offshore racing
Coastal cruising + weekend (8-12 m sailboat)
Recommended solution: Triton² WS320 wireless pack (€1,499) = wireless sensor + 2 Triton² displays + N2K interface, ready to sail. This is a complete pack: to compare not with the 213 head alone (€1,040) but with a full 213 installation (head + spar + cable + display), which exceeds this budget while remaining mechanical. Installation time 1 h, battery life 12-18 months, accuracy more than sufficient for coastal use.
Offshore cruising comfort (35-50 ft sailboat)
Recommended solution: B&G WS710 0.8 m wired (€2,043) + WS310 N2K interface (€155) + 2 Triton² displays (€462 each). Total ~€3,130 material + 6-8 h workshop installation (mast cable run). 10+ year reliability without intervention.
IRC / IMOCA Coastal offshore racing (40-55 ft sailboat)
Recommended solution: B&G WS720S Ocean spec (€2,865) + H5000 CPU Hydra (€1,139) + race displays like 30/30HV (€1,700) + Precision 9 compass (€533) integration. Total ~€6,300 + installation 10-15 h.
Pure offshore racing (IMOCA, Class40, Mini, Figaro)
Recommended solution: NKE 3D HR II + NKE Performance central processor (project quote) or B&G WS730S Ocean (€3,080) + H5000 Performance (€2,899) + Madintec integration for advanced autopilot (see our article on race hydraulic vs. electromechanical ram). Total ~€10,000 material + project 30-50 h.
5 common installation errors observed in the workshop
Anemometer errors — seen in the Skysat workshop
- Sensor misaligned with the boat’s axis. The 0° of the sensor must exactly match the bow of the boat. A 5° alignment error = wind heading reading permanently offset by 5°, with no visible error until the first close-hauled sailing when the polars no longer match. In the workshop, alignment is validated with GPS + compass before commissioning.
- Sensor too low on the mast. Wind is turbulent in the top 20% of the mast (interaction with mainsail, headstay, mast itself). Always mount the sensor 30-50 cm above the masthead for clean wind. On sailboats where the mechanical vane is historically at the masthead, the ultrasonic sensor replaces it but must extend a few cm above.
- Mast cable run parallel to a motor or windlass cable. The anemometer cable carries a very sensitive millivolt signal. Running it next to a cable carrying 80 A at startup induces measurable electrical noise. Always separate signal cables (anemometer, antenna) from power cables (winches, propulsion, starter).
- Commissioning without offset calibration. Each sensor has a manufacturer offset (zero angle correction, speed correction). Not calibrating = accuracy reduced to ±5° instead of ±1°. Calibration takes 10 minutes via the manufacturer’s app or display, but is often forgotten.
- Vertical mounting on a mast that is not vertical. If the boat heels or rigging deforms the mast, the sensor is no longer vertical relative to the waterplane. This introduces a variable offset that depends on heel. 3D models automatically correct this, 2D models do not — plan ahead if the boat’s program involves significant heel.
FAQ — Sailboat anemometer in practice
How high should the sensor be mounted on the mast?
Minimum 30-50 cm above the masthead to avoid turbulence from the mainsail and headstay. On traditional rigged racing sailboats with boomed mainsails, mount up to 80 cm. Higher = cleaner wind, but more windage and breakage risk. 50 cm is a good cruising/racing compromise.
Can I replace a mechanical sensor with an ultrasonic one without changing the existing onboard electronics?
Yes in 90% of cases, provided there is a NMEA 2000 or 0183 interface on the existing electronics. The ultrasonic sensor connects via a dedicated interface (B&G WS310 N2K at €155) and publishes its data on the N2K bus, read by all displays. The existing mast cable can often be reused if the gauge and length are suitable. Validate with an audit before ordering.
How many years does an ultrasonic anemometer last?
Without moving parts, ultrasonic lifespan is limited by electronics and housing watertightness. Field feedback on B&G WS720/WS730: 10-15 years average, sometimes more. NKE 3D HR II: 12-18 years with a service every 5 years. The #1 mortality factor is water ingress (aging gasket) — hence the importance of quality installation and choosing a marine-grade IP67 certified model.
Why does my anemometer read higher wind with full mainsail?
This is the Venturi effect. The mainsail creates an accelerated wind zone at the top of the mast where the sensor measures. Depending on mainsail shape, draft depth, and point of sail, wind amplification of 10-30% in true wind is observed. This is normal and well known — polars are calculated taking this bias into account. If the reading becomes absurd (doubled), there is a sensor or calibration defect.
WS320 wireless — can I control it from my onboard computer?
Yes via the NMEA 2000 interface of the WS320 pack (€449). The wireless sensor sends radio to a base connected to the N2K bus. The onboard computer (or WiFi tablet) then reads the N2K data via a router. Radio latency is 100-200 ms in worst case — invisible for navigation, but noticeable in racing optimization where wired is preferred.
How do I calibrate the 0° offset after installation?
B&G workshop method: (1) boat stationary, GPS fixed, (2) Triton² display wind calibration menu, (3) note the wind heading value displayed, (4) correct the sensor offset so it matches the true wind measured by a reference anemometer or by the drift of a telltale. For NKE: Toplink app or Multigraphic display, wind calibration menu → zero offset. Always do this in calm waters with stable 5-15 knot wind.
Is a 3D sensor mandatory for offshore cruising?
Not mandatory but highly recommended beyond 40 ft in rough seas. The vertical component of the wind (pumping in swell, accelerations over waves) creates errors on a 2D sensor that the autopilot interprets as heading changes — resulting in constant oscillations in rough seas. The 3D filters this. On a 30 ft cruising sailboat in summer, a 2D ultrasonic is more than sufficient.
Skysat distributes B&G, NKE Marine Electronics, Raymarine, Garmin and Navico. This article reflects our experience installing wind sensors on over 60 sailboats 2020-2026, cruising and racing. 2026 HT prices are indicative of the French distributor; technical specifications are from manufacturer datasheets and field measurements during sailing.
