Simrad HS75 Multi-GNSS Compass with 0.75 Degree Heading
Simrad HS75 Multi-GNSS Compass with 0.75 Degree Heading — Product description
The Simrad HS75 GNSS Compass is the commercial-grade GPS compass for serious autopilot, radar, and integrated marine electronics installs. Multi-constellation GNSS (GPS, GLONASS, BeiDou, Galileo, QZSS) for global positioning. 0.75-degree heading accuracy - significantly tighter than a typical magnetic rate compass and at a fraction of the cost of a gyro compass. Accurate heading delivered even when the boat is stationary (where standard GPS receivers can only estimate heading from movement). Integrated gyro and tilt sensors provide backup heading during GPS signal loss. Outputs rate of turn, heave, pitch, and roll over NMEA 2000. 20-times-per-second position updates for fast powerboats. Plug-and-play install on a flat surface or pole.</p>
The Simrad HS75 GNSS Compass (part 000-16143-001) is the commercial-grade GPS compass that delivers accurate heading data to autopilots, radar systems, and integrated marine electronics across the boat. Multi-constellation Global Navigation Satellite System (GNSS) support means the unit tracks satellites from five different systems simultaneously (GPS from the U.S., GLONASS from Russia, BeiDou from China, Galileo from Europe, QZSS from Japan), which dramatically improves position fix reliability and heading accuracy in challenging conditions where any single constellation alone might be partially obstructed.
What a GPS compass does that a regular GPS doesn't. A standard GPS antenna gives you position. To estimate heading, the GPS has to compare two successive position fixes and infer which direction the boat moved between them. That works while the boat is moving forward at reasonable speed. It fails completely when the boat is stationary (no movement = no heading estimate), and it's unreliable at low speeds (small position changes give noisy heading estimates). A GPS compass like the HS75 uses two physically-separated GPS antennas (or in the HS75's case, a calibrated multi-element antenna array) to measure heading directly from the received satellite signals - so the heading is accurate at any speed including dead stop. Critical for autopilot operation when the boat is at zero speed or maneuvering at low speed, and for radar features like target overlay that need accurate heading regardless of boat motion.
0.75-degree heading accuracy. Commercial-grade heading accuracy specification. For comparison: typical magnetic fluxgate compasses spec 1-2 degrees of accuracy, and even those degrade further from magnetic interference. A traditional gyro compass can deliver tighter accuracy than the HS75 but at 5-10x the cost and significant ongoing maintenance. The HS75 hits the sweet spot of commercial-grade accuracy at recreational-marine pricing, without the maintenance burden of a gyro.
Multi-constellation GNSS support. GPS alone provides position fix using up to about 12 visible satellites at any time. Adding GLONASS, BeiDou, Galileo, and QZSS expands the visible-satellite pool to 30+ at any time. More visible satellites means: faster initial position fix at startup, better fix accuracy through better satellite geometry, and far more reliable fix in conditions where some satellites are obstructed (high tree cover, marina channels with structures blocking sky, downtown urban-canyon docking areas). For a critical heading sensor that the autopilot depends on, the multi-constellation reliability matters.
20 Hz position update rate. The HS75 calculates position 20 times per second (compared to the once-per-second update rate of older GPS units). The faster update rate matters for fast-moving powerboats where the boat covers significant distance between updates - at 50 mph, a once-per-second GPS positions the boat 73 feet farther downrange between updates. The 20 Hz rate gives smooth, continuous position display. For autopilot performance at speed, the faster rate also lets the autopilot respond to course corrections faster.
Stationary heading via direct measurement. The HS75 measures heading directly from the satellite signal phase difference between its multi-element antenna - not from boat movement. So the heading is accurate even when the boat is stationary at the dock, anchored, or holding position via Spot-Lock or autopilot anchor mode. For boats running advanced sonar features that depend on knowing the boat's heading (Side Imaging waypoint placement, MEGA Live forward sonar orientation, radar target overlay alignment), the HS75 provides reliable heading at any speed.
Integrated gyro and tilt sensors. In addition to the GNSS-derived heading, the HS75 includes integrated gyro and tilt sensors that provide backup heading data during temporary GPS signal loss. If satellites become unavailable (passing under a bridge, transitioning under a dock cover, etc.), the gyro maintains heading via dead reckoning until GPS signal returns. The integrated approach means continuous heading availability regardless of momentary satellite obstruction.
Rate of turn, heave, pitch, and roll. In addition to heading, the HS75 outputs rate of turn (essential data for optimal autopilot performance - the autopilot uses ROT to anticipate course corrections), heave (vertical wave-induced motion - some sonar equipment uses heave data to compensate for wave action so the sonar image stays steady), pitch (boat angle nose-up / nose-down), and roll (boat angle port-starboard). The full motion data set is output over NMEA 2000 to compatible equipment that can use it.
NMEA 2000 output. All HS75 data outputs over NMEA 2000 - the standard marine instrument network. Connect the HS75 to the boat's existing NMEA 2000 backbone, and any compatible chartplotter, autopilot, radar processor, or sonar unit on the network reads the heading and motion data automatically. No proprietary protocol, no vendor lock-in. The HS75 works with the broader NMEA 2000 ecosystem from any compatible chartplotter brand.
SBAS augmentation. Satellite-Based Augmentation System (SBAS) support means the HS75 receives positional correction signals from regional augmentation satellites (WAAS in North America, EGNOS in Europe, MSAS in Japan, etc.) where available. SBAS corrections improve position accuracy from typical 2-3 meters down to under 1 meter. For boats that need the tightest possible position accuracy (commercial fishing, hydrographic survey, precision navigation), SBAS gets you there.
Plug-and-play install. The HS75 is engineered for simple install. Mount the unit (35 cm long, compact form factor) to a flat surface or pole using the supplied mounting hardware. Connect to the boat's NMEA 2000 backbone via the supplied Micro-C cable. Power on. The unit auto-acquires satellites and starts outputting data. No commissioning steps, no field calibration, no orientation alignment to set. The auto-detect orientation calibrates the unit to its install position automatically.
Mounting location matters. Best practice: mount the HS75 in a clear-sky location away from large metal masses (radar arches, t-top frames, big speakers). Top of the boat (radar arch, hardtop) is the best location for satellite visibility. Avoid mounting directly under radar antennas or other electronics that emit RF energy. The HS75 includes detailed mounting instructions for the various typical install configurations.
What this isn't. It's not a chartplotter (it's a heading sensor that feeds data to your chartplotter). It's not a regular GPS antenna (it's a GPS compass with both position AND heading capability - you can use it as both a position source and a heading source). It's not a satellite compass for sub-degree accuracy applications (those cost 5-10x more and target the largest commercial vessels). For 0.75-degree heading accuracy at recreational-marine pricing with the multi-GNSS reliability, the HS75 hits the sweet spot.
What's in the box. HS75 compass / GNSS antenna unit, NMEA 2000 cable, mounting hardware, install instructions. Required separately: NMEA 2000 backbone (or NMEA 2000 starter kit if not already on the boat).
2-year limited Simrad warranty. Same-day shipping before 3 PM ET on in-stock units.
Key Features
- Commercial-grade multi-GNSS GPS compass with 0.75-degree heading accuracy
- Multi-constellation GNSS: GPS + GLONASS + BeiDou + Galileo + QZSS
- Accurate heading delivered at any speed including dead stop
- 20 Hz position update rate for fast-moving powerboats
- SBAS augmentation support (WAAS / EGNOS / MSAS) for sub-meter positioning
- Integrated gyro and tilt sensors for backup heading during GPS signal loss
- Outputs rate of turn, heave, pitch, and roll in addition to heading and position
- NMEA 2000 output (works with any compatible NMEA 2000 chartplotter / autopilot / radar)
- Plug-and-play install with auto-orientation calibration
- Compact 35 cm form factor mounts to flat surface or pole
- Manufacturer Part Number 000-16143-001
- 2-year limited Simrad warranty
Why Buy from NVN Marine
- Authorized Simrad reseller, full manufacturer warranty
- NMEA member and ABYC certified, advice from real boat techs
- Same-day shipping before 3 PM ET on in-stock items
- NY headquarters and Fort Lauderdale flagship retail store
Technical specifications
| Title | Simrad HS75 Multi-GNSS GPS Compass with 0.75-Degree Heading Accuracy |
|---|---|
| Brand | Simrad |
| Manufacturer Part Number | 000-16143-001 |
| UPC | 9420064131570 |
| Type | GPS / GNSS compass (heading sensor + position antenna) |
| Heading Accuracy | 0.75 degrees |
| GNSS Constellations Supported | GPS + GLONASS + BeiDou + Galileo + QZSS |
| SBAS Support | Yes (WAAS / EGNOS / MSAS) |
| Position Update Rate | Up to 20 Hz |
| Heading at Stationary | Yes (direct measurement, not movement-derived) |
| Backup Heading During GPS Loss | Integrated gyro and tilt sensors (dead reckoning) |
| Additional Outputs | Rate of turn, heave, pitch, roll |
| Output Protocol | NMEA 2000 |
| Mounting | Flat surface or pole (hardware included) |
| Form Factor | 35 cm length compact unit |
| Calibration Required | No (auto-detect orientation, plug-and-play) |
| Warranty | 2-year limited Simrad |
Frequently asked questions
Why a GPS compass instead of a regular GPS?
A standard GPS antenna gives position. To estimate heading, the GPS compares two successive position fixes and infers which direction the boat moved between them. That works while moving forward at reasonable speed but fails when stationary (no movement = no heading estimate) and is unreliable at low speeds. A GPS compass like the HS75 measures heading directly from the satellite signal phase difference between its multi-element antenna, so heading is accurate at any speed including dead stop. Critical for autopilot at zero speed or low-speed maneuvering, and for any electronics that need accurate heading regardless of boat motion.
What's 0.75-degree heading accuracy mean?
The HS75's measured heading stays within 0.75 degrees of true heading at any moment. For comparison: typical magnetic fluxgate compasses spec 1-2 degrees, and they degrade further from nearby magnetic interference. A traditional gyro compass can deliver tighter accuracy but at 5-10x the cost and significant maintenance. The HS75 hits the commercial-grade accuracy point at recreational-marine pricing without the gyro maintenance burden.
Why multi-GNSS instead of just GPS?
GPS alone gives you up to about 12 visible satellites at any time. Adding GLONASS, BeiDou, Galileo, and QZSS expands the visible-satellite pool to 30+ simultaneously. More visible satellites means faster initial position fix at startup, better accuracy through improved satellite geometry, and far more reliable fix in conditions where some satellites are obstructed (tree cover, marina channels with structures, urban-canyon downtown docking areas). For a heading sensor the autopilot depends on, the multi-constellation reliability matters.
Will it work with my chartplotter?
Yes, with any NMEA 2000-compatible chartplotter. The HS75 outputs all data (heading, position, rate of turn, heave, pitch, roll) over standard NMEA 2000 - no proprietary protocol, no vendor lock-in. Connect the HS75 to your boat's NMEA 2000 backbone, the chartplotter reads the data automatically. Works equally well with chartplotters from any major marine electronics brand.
What does Rate of Turn data do?
Rate of Turn (ROT) is how fast the boat is currently rotating in degrees per second. Autopilots use ROT data to anticipate where the boat will be in the next moment - allowing the autopilot to make smaller, smoother course corrections instead of overshooting and oscillating. For optimal autopilot performance on any boat, ROT data is essential. The HS75 calculates ROT directly from the GNSS measurements and outputs it over NMEA 2000.
What's heave compensation?
Heave is the vertical wave-induced motion of the boat - the up-and-down movement as waves pass under. Some advanced sonar equipment uses heave data to compensate for the up-and-down motion so the sonar image stays steady on the screen even in choppy water. Without heave compensation, every wave shifts the sonar return up and down on the screen and makes the bottom look like it's moving when it's not. With heave data from a unit like the HS75, the sonar can correct for the boat motion.
How fast does the position update?
Up to 20 times per second (20 Hz) - much faster than older GPS units that update once per second (1 Hz). The faster rate matters for fast-moving powerboats: at 50 mph, the boat covers 73 feet between 1 Hz updates. At 20 Hz, the position display stays continuous and smooth. For autopilot performance at speed, the faster rate lets the autopilot respond to course corrections faster.
What if I lose GPS signal?
The integrated gyro and tilt sensors maintain heading during temporary GPS signal loss via dead reckoning. If satellites become unavailable for a short period (passing under a bridge, transitioning under a dock cover, etc.), the gyro continues delivering heading data until satellite signal returns. Dead reckoning accuracy degrades over time, so for extended satellite outages you'd need to re-acquire signal eventually. For typical short-duration obstructions, the gyro backup keeps the autopilot and other connected systems functional.
Where do I mount it?
Best practice: mount in a clear-sky location away from large metal masses (radar arches, t-top frames, big speakers). Top of the boat (radar arch, hardtop) is the best location for satellite visibility. Avoid mounting directly under radar antennas or other electronics that emit RF energy. The HS75 has a compact 35 cm form factor that mounts to either a flat surface or a pole using the supplied hardware. Detailed mounting instructions cover the typical install configurations.
Do I need to calibrate it?
No. The HS75 is plug-and-play. Mount it, connect to the NMEA 2000 backbone, power on. The unit auto-acquires satellites and starts outputting data. The auto-detect orientation calibrates the unit to its install position automatically. No field calibration steps, no orientation alignment to set, no commissioning to perform.
Will it improve my autopilot performance?
Yes, significantly, especially if your boat currently has only a magnetic fluxgate compass. The 0.75-degree heading accuracy plus the rate-of-turn output gives the autopilot much better data to work with than a fluxgate provides. Autopilot heading-hold is tighter (less wandering off course), course corrections are smoother (less overshoot and oscillation), and at-speed performance improves with the 20 Hz position updates. For boats that fish or cruise with autopilot frequently engaged, the HS75 is a meaningful upgrade.
What's the warranty?
2-year limited Simrad warranty. Service runs through the Simrad authorized service network in the U.S.
