The magnetic north pole “has moved more in the last 15 years than in the 50 years before that" (1). It is now moving 37-50 miles (60-80 km) per year (2, 3).

Invisible Forces - World Magnetic Map
 Announcing WMM Update to Wind Instrument

Traditionally, masthead anemometers were calibrated to the bow of the boat and only measured wind angle relative to the boat. However the wireless, solar-powered SailTimer Wind Instrument™ has a digital compass inside the wind direction arrow. It can provide wind direction as well as wind angle. If you want to view or share your wind conditions on a map, this is what you need. The marine weather forecast doesn't tell you wind angle, it tells you wind direction.

GPS displays, marine charts and the marine weather forecast are with reference to True North. But since compasses measure the earth's magnetic field towards Magnetic North, compass data needs to be converted to True North. For spring 2021, we are pleased to announce a major new update to the SailTimer Wind Instrument based on the NOAA - UK World Magnetic Map (shown above). This new model still has the same physical design innovations: no wires to run down the mast, transmission range of 270' (85m), works on rotating masts, for boats of all sizes, and can be raised without needing to lower or climb the mast. But this new model has all-new firmware in the electronics, giving you some powerful new features...
The SailTimer Wind Instrument provides all of the wind types.

Features in New Wind Instrument

• Magnetic Declination: This is the angle between magnetic north and true north. This angle varies depending on your location and changes over time. The new Wind Instrument model calculates declination with the state-of-the-art NOAA / British Geological Survey World Magnetic Model (WMM), to get precise wind direction worldwide. A customer shared an example with us from the CORK regattas in Kingston, Ontario, Canada. This 1980 article documents a 30-degree magnetic anomaly along the Kingston waterfront. If you are planning tacks to a waypoint or finish line, 30 degrees could make a huge difference. So you want accurate wind direction based on your precise location. Plus, the magnetic north pole is moving so the 1980 findings will not be the same now. For example, in Fairbanks Alaska USA there has also been a 30-degree change in magnetic north over the last century (ref). Marine charts account for this by adding a compass rose (a.k.a. wind rose) with the magnetic declination and date, which you then need to apply (recognizing that if you are using a 10-year-old chart, the Magnetic North Pole will have moved hundreds of miles since the chart was printed). With wind direction, the SailTimer Wind Instrument does all of this automatically for you.

• Over-The-Air Updates: Completely rewriting the firmware in the Wind Instrument means that you can now get Over-The-Air (OTA) Updates through the API for new electronics functions that may become available in future.

• Tilt Invariance: Traditionally, needle and card compasses need special arrangements for use on a heeling sailboat, such as gimbals or floating in a glass sphere to remain horizontal. This is also complicated because the earth's magnetic force is horizontal at the equator, and approaches vertical near the North and South Poles (as shown in this interesting illustration and this one). For the Northern Hemisphere, some good mechanical compasses have a weight on the South side of the needle, knowing that there is going to be downward force on the North side. The SailTimer digital compass uses an inertial motion unit (IMU) including gyro and accelerometer to account for these factors. With the new model, elaborate compass calibration is done in the factory on a special machine as each Wind Instrument goes through the production line. This allows the digital compass to maintain accurate wind direction regardless of heeling. Our innovative wind cups are also designed to remain accurate when heeling, and turn into propellers when you sail along heeled over. All other types of anemometers lose accuracy on heeling sailboats.

• Transmission Speeds Up to 20 Hz: Ten years ago when SailTimer made the first-ever masthead anemometer that could transmit to smartphones, the technology could only handle transmissions once every 2 seconds because of limits on power consumption. When the new vertical design came out in 2014, the development team was thrilled when we could double the transmission speed to 1 Hz (1 transmission per second) by using Bluetooth Low Energy. Now we are pleased to announce a further breakthrough in transmission rates of 1, 3, 5, 10 or 20 transmissions per second (Hz). For sustainable battery power consumption, use 1 or 3 Hz. But if you have a racing boat or trailer-sailor that comes out of the water regularly, or if you want extremely fast data for an auto-pilot even if the power consumption is not sustainable indefinitely, you now have the option to increase the transmission speed to 5, 10 or even 20 Hz (which may even be too fast for some smarthones and tablets). Fast transmissions make a wind gauge move smooth as silk with no lag.

Get the New Model Now For Spring Launching

The Wind Instrument RB™ has a Replaceable Battery which is used as a counter-balance in the nose cone. It is lighter than previous models with a carbon-fiber pointer. It uses ceramic bearings which are very reliable, perform well and cannot corrode. The tail enclosure is a lightweight clear shell that is sealed with ultrasonic welding to make it watertight and submersible. There is an LCD wall charger in the Accessories which makes it easy to top up the battery if needed in the off-season. And the Wind Instrument works with many different navigation, wind gauge and performance apps.

We are not aware of any other digital compasses or anemometers that have announced using NOAA's new WMM model given the rapidly-changing World Magnetic Map. Imagine if your anemometer compass was accurate when manufactured but lost accuracy when shipped to your location. Or if it was accurate at your location, but not when you go off cruising. Or if you were at the CORK Regatta (above) and find that a North wind is 30 degrees different at each end of the waterfront. That would not be acceptable. NOAA's World Magnetic Model (WMM) allows the SailTimer Wind Instrument to calculate accurate wind direction by date for all locations worldwide.

The new model is shipping now. It will take a few weeks to catch up on the waiting list and get back to 2-day shipping. Get the leading technology for just $549.99 or with low monthly payments. Order now for earliest delivery.


Copyright © 2021 SailTimer Inc. All rights reserved. SailTimer, Air Link, SailTimer Wind Instrument, Wind Instrument RB, Audio Navigation, TTD® and the above tacking logo are trademarks of SailTimer Inc.

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