Where sailboat navigation is going in 2020

In the Australian sailing news four years ago, there was an article about the SailTimer Wind Instrument being the first masthead anemometer with an internet connection, and some of the implications that would have. Those capabilities have all been realized, and there is a new model called the Wind Instrument RB with a Replaceable Battery and many new innovations and improvents. The team of developers at SailTimer has been working on the next generation of high-resolution wind zones, beyond anything currently possible with GRIB and marine weather forecasts. As this year draws to an end, here is an update on how shared wind and weather data (crowdsourcing) will have fundamental changes for sailboat navigation in 2020…

Growth in crowdsourced data: There are over 3 years of data in the SailTimer cloud database. In last 18 months users have shared over 17-million data points.

The original goal for in 2016 was displaying clickable data points on a map at SailTimerMaps.com. But we now want to visualize those as wind zones for planning tacking routes. Currently with the best technology available you can only plan optimal tacking routes based on the Wind Instrument on your masthead.

GRIB is the standard data source for marine weather forecasts (Wikipedia explanation here). But it is not even based on actual wind measurements; it is based on satellite imagery of air pressure – hence the low resolution. For example in the US, NOAA has the last 5 days of GRIB data in 0.5-degree resolution (cells 15×15 nautical miles) and keeps older data in 0.5-degree resolution (cells 30×30 nautical miles wide). But everyone knows the wind is not uniform within giant regions; it flows around headlands, and funnels down channels.

Crowdsourcing wind maps is a transformational new approach, like the Waze app or Google Maps showing traffic flow based on user data. Imagine if you could plan tack headings for wind zones up ahead. Is the wind more favorable close to shore or out on the open water? How much tacking will you have to do through an upcoming channel? What is the wind doing behind that island? Crowdsourced wind zones can tell you.

Crowdsourced wind zones in this draft visualization have much higher resolution than a GRIB or marine weather forecast.

The map above has contour lines showing wind direction, and wind barbs from each data point. Wind barbs are a meteorology symbol that provides an arrow to indicated wind direction, with the number of “feathers” on the tail indicating wind speed. We are still refining this preliminary visualization, but the map and wind zones are generated automatically from the database for whatever location you want to view. Because the Wind Instrument transmits once per second (and soon faster, with an update in the new year), when sailing along we get a resolution of about 1 boat length. If there are multiple data points in one location, those are averaged in cells with a resolution of 30 feet/10 meters, not giant coarse cells 15 to 30 miles wide.

High-resolution wind maps from crowdsourcing allow you to plan tack headings using wind zones up ahead.

An overlay with high-res wind zones will be added to the free SailTimer chartplotter app shown above, and will be made available under free license to other apps and weather platforms.

But what happens if there is no-one sharing data in the particular location you want to view? That is the usual problem with crowdsourced data, but there is a great solution in this case… When a user shares wind data in a particular location, we archive that data and match it up with the marine weather forecast for that precise location. Then in future if you need to see a high-res wind map, we can search back to any previous data for that location with the same wind direction in the forecast. Even in a location with only one boat sharing data, that boat can cover an entire coastline and a lot of wind conditions over the course of one season.

You don't even need an internet connection out in the boat to see these high-res wind zones. GRIB and marine weather forecasts project hour by hour, so before leaving your normal wifi or internet connection you can get the most recent wind map of crowdsourced data merged with the marine weather forecast for the next hours or days. Then if the forecast is from a certain direction, you'll know what the wind will be actually doing in a certain anchorage or how it will be funneling down a certain channel.