Racing Instruments Compared: B&G vs Garmin vs Raymarine

This is an independent, objective comparison — we hold no partner among electronics brands. It rests on published specifications and known ecosystem behaviour, not a hands-on test on our own boat; field reviews of our actual fit and calibration to follow.

A racing instrument system is not a chartplotter with a wind gauge bolted on. It is a real-time signal-processing chain: a masthead sensor of finite bandwidth, an inertial reference measuring the boat's motion, a processor solving true wind and target functions at some update rate, and displays and tactical software that only ever show you a derived number. Every link degrades the last. This compares the three ecosystems on the parts of that chain that decide a race — not on cartography, which barely matters on a windward-leeward course. For the fundamentals, see our race-boat electronics guide and the B&G research note.

At a glance

The engineering that decides it

Processor: update rate and filtering, not marketing headline speed

This is the axis race boats actually buy on, and it is where the three ecosystems diverge hardest. B&G is the only one of the three that ships a dedicated performance CPU whose job is to solve sailing maths — Garmin and Raymarine fold the calculations into the chartplotter's general-purpose SoC.

Within B&G the split matters. The H5000 Hydra/Hercules CPU (dual ARM on Hydra) computes wind at roughly 35 Hz, per B&G, varying slightly with sensor count. The current-generation Hercules processor — a quad-core — pushes that to 80 Hz, or 100 Hz with INDYN sensors, with substantially rewritten filtering. The legacy WTP3, still the reference on many professional programmes, was built expressly for the navigator and adds custom-maths capability, dozens of sensor channels and user-augmentable calibration datums.

Why does 35 Hz versus 100 Hz matter when your eye can't read a number that fast? Because the filtering that turns a noisy, motion-contaminated wind signal into a stable but responsive displayed number is a trade-off between latency and jitter. A higher raw sample rate gives the filter more to work with, so it can damp the twitch of a chop-induced oscillation while still surfacing a genuine 5° header quickly. On the low-rate path you are forced to choose: damp hard and the shift arrives late, or damp light and the trimmer is chasing noise. That is the practical difference between "the number told me to tack" and "the number lied twice before it told me to tack." For a Grand Prix boat this is the whole game.

Motion correction: the true-wind solution is an inertial problem

Apparent wind at the masthead is corrupted by the boat's own motion — as the mast tips to windward in a puff or pitches into a wave, the sensor sees an induced wind that has nothing to do with the breeze. Correcting it is not arithmetic on heel angle; it needs the rates of pitch and roll, measured by a gyro, so the processor can compute the velocity of the sensor through the air at masthead height and subtract it. This is why B&G describes its solution as taking "high-specification rate-gyros to correct for induced wind."

The sensor behind that correction is where the tiers separate. B&G's 3DMotion refreshes attitude and rates at about 35 Hz with roughly 10 cm / 1° dynamic resolution; the higher-grade INDYN unit does better than 100 Hz at 1–5 cm and rate-of-turn resolution around 0.1–0.01°. Feed INDYN into Hercules and both the sensor and the solver are running at 100 Hz — the numbers stay planted through a tack instead of spiking. B&G explicitly re-tuned the H5000 true-wind solution "to match our WTP3 Grand Prix system" for stability during manoeuvres while staying responsive.

Garmin and Raymarine do not offer an equivalent rate-gyro true-wind pipeline. Garmin's answer is the AIRMAR DST810 smart triducer, which supplies heel/trim and pitch/roll from an internal sensor and feeds heel-corrected data over NMEA 2000 — genuinely useful, and a real step above a bare depth/speed transducer, but it is a heel-compensation input, not a masthead motion-cancellation solution. Raymarine's Axiom carries an internal AHRS and its instrument stack applies attitude data, but again it is not marketed or engineered as a Grand Prix motion-correction system. For inshore one-design in flat water the gap narrows; the moment there is a seaway and the masthead is describing arcs, it widens sharply.

The masthead sensor: bandwidth and inertia at the top of the rig

Everything downstream is limited by what the sensor at the masthead can resolve, and here the interesting comparison is within the B&G ecosystem. The venerable B&G 213 is a three-cup anemometer with a mechanical vane putting out analogue/pulse signals — ocean-proven, repairable, and the reason it survives on so many boats. But B&G's own digital wands carry several seconds of built-in damping, which is a liability for motion-compensation maths that want the rawest possible signal to work from.

That is precisely the gap the aftermarket exploits, and it is standard practice on Grand Prix B&G boats. The A+T 500-series wind sensor uses a carbon wind vane with the vane and counterbalance mass pulled as close to the axis as possible, minimising moment of inertia so the vane tracks fast, gusty shifts without lag. A+T calibrates each unit to 0.2°, outputs NMEA 0183HS at 20 Hz with no damping, and — critically — uses the same mast cable and bracket as the 213, so it is a bolt-on upgrade to any B&G system, old or new. Undamped 20 Hz data is exactly what a rate-gyro motion solver wants as its input; damped data smears the correction. B&G's own newer sensors follow the logic: the WS300 (wired) and the vertical-profile WS700 are the recommended replacements for new installs, with the vertical unit reducing the downwash/upwash error that a horizontal cup-and-vane suffers at deep apparent angles.

Garmin's gWind Wireless 2 is a well-executed convenience play — an integrated solar-charged cell rated up to three years, sending data over Garmin's proprietary ANT link. Two engineering consequences follow. First, it transmits apparent wind only, computing true wind downstream in the chartplotter from GPS and heading, which means the quality of your true wind is bounded by your COG/SOG/heading calibration rather than by a purpose-built inertial correction. Second, ANT is a low-power telemetry protocol, not a high-bandwidth instrument bus — fine for a cruiser or club racer, but not the pipe a Grand Prix motion solution would choose. Raymarine keeps a conventional analogue vane but routes it through the iTC-5 instrument-transducer converter to digitise depth/speed/wind/compass/rudder onto the SeaTalkng/NMEA 2000 network — a clean way to keep proven analogue sensors while modernising the head units.

Loadcell and rig-load inputs: the Grand Prix differentiator

This is where the ecosystems stop being comparable. A Grand Prix instrument system ingests linear load and position sensors — forestay load, keel-ram or canting-keel angle, daggerboard rake, sheet loads — and folds them into the picture the afterguard reads. B&G's WTP3 and the Hercules WTP were built for exactly this: the WTP line accepts loadcell data, supports custom maths on those channels, and pushes it all onto the FastNet/N2K bus into the tactical software. On a canting-keel one-design like the Melges 40, forestay load and keel-cant feedback are not luxuries — they are core trim and safety data, and only the B&G performance line handles them natively as first-class inputs.

Garmin's sailing stack has no equivalent — there is nowhere to bring a forestay loadcell into gWind/GNX/SailAssist. Raymarine can display third-party load data if it is put onto NMEA 2000 by an external sensor system, but there is no dedicated loadcell-plus-custom-maths performance layer. For a strict Grand Prix programme this alone often ends the discussion.

Tactical software integration: who owns the pipe

The instruments are only as good as the software the navigator drives, and integration depth is not equal. B&G's advantage here is historical and structural: B&G bought Sailmath — the WTP hardware and Deckman navigation software — in 2004, so Deckman is effectively in-house, and Expedition and Adrena integrate with the Hercules WTP and WTP3 as a matter of course. That means every derived channel, every loadcell input and every custom calculation flows into the tactical PC without protocol gymnastics. This is the reason a professional navigator's boat is almost always B&G-plus-Expedition: the data model was designed to feed that software.

Raymarine has closed a lot of ground inside its own displays. The Axiom2 Pro S with LightHouse ships genuine racing tools as standard: SmartStart start-line management, real-time dynamic laylines computed from over 500 built-in polar profiles (or fixed angles), adjustable race timers and tactical dial indicators — and the T070 Race Master tactical compass gives a two-tier readout of heading, mean-course delta and header/lift state for crews who want a dedicated shift indicator. It is a strong, self-contained club-and-inshore package; it is simply not built to be the sensor backbone under Expedition on a professional boat.

Garmin's SailAssist is the equivalent on-MFD suite — laylines, wind-rose data, wind angles and polar data — and it is legitimately capable for the money. The honest caveat, which applies to all three laylines-from-polars implementations, is that a layline is only as trustworthy as its inputs: it needs well-calibrated leeway, set/drift, boat speed, heel and heading, and a polar table adjusted to what the boat actually does versus the VPP prediction. And every polar-based system misleads pre-start, where you are manoeuvring below target speed without the downwind sail set, so the layline geometry assumes an equilibrium you are not in. That is a physics limitation of the method, not a brand failing — but B&G's Starline pre-start maths and the depth of Expedition's start-line tools address it more directly than the lighter suites do.

Displays: brightness, latency and power

For the head units the axes are readability in glare, refresh latency and current draw. B&G's Nemesis 9" and 12" displays are super-bright colour touchscreens quoted at 1300 nits, IP67, with drag-and-drop dashboards and automatic mode switching (pre-start, upwind, reaching, downwind, motoring) over 100 Mbit Ethernet and/or NMEA 2000; the HV colour displays and legacy Triton² round out the range and interoperate. Raymarine's Alpha Performance Displays are the analogue in that tier — large, high-brightness, race-oriented — with the i70S as the compact all-rounder.

Garmin plays this differently and shrewdly: the GNX 20 / GNX Wind are glass-bonded monochrome LCDs with customisable backlight colour and, notably, a 350–400 mW power draw. On a boat running instruments off a modest battery through a long offshore leg, a monochrome display sipping under half a watt is a real systems advantage — high-nit colour touchscreens cost you amp-hours. It is a deliberate trade of graphical richness for readability-in-any-light and negligible load, and for the right boat it is the correct call. See our race-yacht battery system note for why that draw matters over a full day's racing. Dedicated racing repeaters such as Sailmon are frequently added on top of any of these brands where the crew wants a single huge, glanceable number at the mast.

Our take

With no partner here, the engineering verdict is unambiguous for the top of the sport. For a Grand Prix keelboat — and specifically for a canting-keel one-design like the Melges 40 — B&G is the only ecosystem of the three that closes the whole chain: a dedicated performance processor solving wind at 80–100 Hz, a real rate-gyro/INDYN motion-correction pipeline, native loadcell and custom-maths handling for forestay and keel inputs, an aftermarket path to undamped 0.2° A+T sensors on the existing bracket, and Deckman/Expedition/Adrena integration that was quite literally designed around this hardware. Nothing Garmin or Raymarine sells competes on those axes, because neither is trying to.

That is not a knock on the other two for the boats they suit. Garmin delivers 90% of the visible sailing features for a fraction of the spend, with a smart low-power display strategy and a solar wireless masthead that a race-and-cruise owner will love — the ceiling is lower, but so is the price and the fuss. Raymarine's Axiom Pro S is a genuinely strong self-contained club-and-inshore racing package with the best cartography of the three and now-credible tactical tools; if charts and cruising lead the brief and racing is club-level, it is the coherent choice.

Our pick: for a dedicated Grand Prix race boat, B&G (Hercules WTP or WTP3, INDYN motion sensor, A+T masthead, Deckman/Expedition) is the engineering answer, and it isn't close on the axes that matter. Choose Garmin for the best value and a race-and-cruise mix where absolute wind-data fidelity isn't the priority; choose Raymarine when cartography and cruising lead and the racing is club-level.

Who each is best for

• B&G — Grand Prix and serious inshore/offshore race boats needing motion-corrected true wind, loadcell inputs and native tactical-software integration.
• Garmin — value-focused sailors and race-and-cruise boats wanting strong on-MFD tactical features and the lowest power draw.
• Raymarine — charts-and-cruising-led boats that also club race, wanting Axiom cartography with built-in SmartStart/laylines.

The takeaway

The badge decides less than the calibration. A Hercules-plus-INDYN system that was never given leeway tables, heel-corrected upwash and a boat-matched polar will lose to a well-set-up Garmin — B&G themselves note most H5000 boats never reach their potential. Buy the hardware whose ceiling matches your ambition, then spend the time to reach it: for Grand Prix that ceiling is B&G's, but the amp-hours, the money and the setup discipline are all part of the real decision. We'll document our actual fit and calibration in field reviews. See what electronics you actually need.