Weather Apps for Yachtsmen

Although seafarers have successfully navigated the oceans before the advent of route-calculating weather programs, current offerings not only reduce travel times, but also provide greater comfort during crossings. What's more, some of these applications work well with low-cost, low-bandwidth satellite communications, giving mariners accurate predictions from virtually anywhere in the world. In this post, we'll look at how these technologies work and how you can get them without gutting your yacht piggy bank to the last cent.

Raymarine Axiom chart plotters allow users to download weather GRIB files from Theyr.com read-only

Meteorological plotting programs may seem complicated - and their invisible calculations really do not fall into the category of "simpler turnip" - but for the end user there are only two aspects of information that are important. The first is an accurate weather forecast received in the "mushroom" format (GRIB, GRIdded Binary - the compressed data format used in meteorology for storing historical and projected weather data). And the second - the characteristics of the boat itself in the form of tables. These tables are developed by boat manufacturers for each model separately and predict boat speed at different wind speeds and angles. It is important to note here that if private meteorological services use mushrooms, the initial data for these files is collected by various government organizations such as the National Oceanic and Atmospheric Administration. (National Oceanic and Atmospheric Administration, NOAA) and turn into open files of the World Forecasting System (Global Forecast System, GFS files) every six hours.

European Center for Medium-Range Weather Forecasts (European Center for Medium-Range Weather Forecasts, ECMWF) produces paid "mushrooms" twice a day.

The National Oceanic and Atmospheric Administration (NOAA) collects primary meteorological data, which becomes the initial information for forecasts

Once released, this data can be used by any third party to create predictions based on proprietary proprietary algorithms. For example, PredictWindavailable as an app for Windows, Mac, Android and iOS, or as a cloud service, offers two proprietary predictions: the data-driven PWG Global Forecast System and PWEusing data from the European Center. “We are the only privately-owned company in the world that produces complete global meteorological models twice a day with two calculations,” says Nick Olson, one of the main developers PredictWind.

Most of the data from the Global Forecast System is in the public domain.

And although long-term (sometimes up to 16 days) GRIB files are publicly available, every reasonable navigator understands that the latest forecasts are always superior to the previous ones. Also, given the size of some "mushrooms", the possible costs of obtaining them and the time required for loading, navigators are more likely to prefer to download only the forecast that they specifically need, and not files for the entire region.

When planning a trip, the navigator loads mushroomsthat cover the area from point A to point B and imports this data into the meteorological software - application or cloud - along with the calculated exit "window". "The plotter takes into account the weather forecast for the planned trip and the indicative travel plans, since it knows the speed of the boat in different weather conditions," explains Olson. Additionally, such programs, based on specific parameters set by the user, can help him determine the optimal departure time and route. Such parameters can include the maximum allowable wind speed or wave height, as well as the percentage of time that the boat will be at a certain point in the route.

FastSeas offers a cloud service that calculates the route based on weather conditions

Advanced navigators use weather forecaststo ensure a comfortable transition, reduce engine travel time and - most importantly - calculate the fastest and most efficient course to your next stop. Depending on the program, some services (for example, the same PredictWind) will create several possible routes based on different meteorological models (GFS or ECMWF) or different departure times, allowing navigators to compare and evaluate their capabilities. “Users still make their own decisions and have to understand the weather,” Olson said. “We warn yachtsmen not to blindly follow the instructions of the service - we strive for them to have more complete information and understand in which weather zone they are”.

Such software can be stored on the onboard computer or in the cloud. In the first version, on a computer with weather programs like AdrenaorTimeZero, the user downloads the "mushrooms" and imports them along with the desired destination (and any points along the route) into the program, which also processes the boat data, creating the best route. Depending on what software is used, the skipper enters boat information manually (usually available from the manufacturer or online) during software installation, or can search for such information in the software's own database. Also with services like PredictWind, the user loads "mushrooms" and imports them into the application itself.

In the second case, the user subscribes to cloud weather plotters, likeFastSeasfrom Amazon Web Services or web servicePredictWind, where he creates his account with information about the vessel. FastSeas allows users who do not know the characteristics of their boat to enter the length of the vessel at the waterline and the best course over the wind, and the program will calculate the approximate characteristics, which the user can already "finish" manually, achieving greater accuracy.

Once having created an account, the user can access it either through the website of the service provider or using satellite communications with low bandwidth (more on this below). Sites usually allow users to visually see their route.which is sometimes placed at the top of the map along with an animated weather video. Low-throughput plotters use small e-mail files that display well the list of waypoints entered into the navigation system, as well as predict the weather upon arrival at each point.

Alternatively, some chart plotter manufacturers like Raymarineallow subscribers to view uploaded "mushrooms" on their plotters as read-only graphics files (Raymarine receives its weather data fromTheyr). This is certainly not a route planner, but such information is still useful for assessing the weather and creating a transition plan that the skipper makes on his own. “Services like these show you the forecast graphically, but you have to know how to interpret all these arrows and icons,” says Jim McGowan, marketing manager Raymarine in America.

In order to work independently with GRIB files, the skipper must be able to interpret the icons and symbols used

If NOAA and ECMWF create GRIB files several times a day, the characteristics of the boat do not change (we are not talking about some independent improvements). Therefore, it is so important that the correct information is entered. Otherwise, the weather plotter will rather quickly turn into an input / output of useless information. “The characteristics of the boat are just as important as the weather data. Because it is from calculating these parameters where you end up, ”says Olson. He adds that users always get the best out of their investment in a sailboat if they have studied the characteristics of the yacht and tested the program before the big transition... “Some might discover that their boat is not sailing 9 knots at 45 degrees to the wind, and this must be taken into account,” says Olson.

Regarding loading GRIB files, then yachtsmen who sail near the coast in the area of \ u200b \ u200bmobile communication or coastal Wi-Fican get them easily. But, of course, on the high seas it is more and more difficult. Typically boaters use a SSB radio along with modems Pactorto have access to the mushrooms. However, in recent years, the price of satellite communications equipment and the cost of airtime have been gradually decreasing. And although there are solutions likeVSATorFleetBroadbandThere is no physical or aesthetic sense for cruise boats less than 60 feet to install an antenna if satellite phones or other relatively low-cost equipment can be preferred.

Garmin inReach - satellite communicator using the Iridium network

"Installing a SSB radio is expensive and not very user-friendly," says Jeremy Waters, owner and creator FastSeas and an experienced amateur radio operator. He notes that if you already have a SSB receiver, the cost of downloading mushrooms can be quite small with accounts on Winlink or Sailmailbut using Garmin inReach or Iridium Go may be cheaper.

Olson agrees. “SSBs still have a surprisingly large market share, but we don't recommend using them. We recommend to our clients Iridium Go... The main reason is that this will give you comprehensive data. We recommend updating the mushrooms twice a day, as the best forecast is the one made last, ”he says. Although the speed Iridium Go and reminds of old days dial-up connections, the service nevertheless allows the user to download GRIB file in just a couple of clicks. And it will automatically resume downloading data if the connection is broken, and will not start downloading it again.

Satellite terminal Iridium GO

Also, satellite offerings have recently appeared on the market that do not require a lot of bandwidth. - such as a satellite communicator Garmin inReach and Mazu mSeries... Using both, users send and receive small packets of information over the network Iridium Short Burst Data (SBD)... If the connection is broken in the process, then after resuming the system continues loading from the moment of the break, and does not return to the start. These products do not have enough bandwidth for Internet surfing or voice communication, but on the other hand give the user the opportunity to receive up-to-date meteorological information... Service Iridium Short Burst Data, which provides almost ubiquitous connection, also supports text messages up to 160 characters (Garmin inReach) or let you download files GRIB (Mazu).

Mazu mSeries runs on Iridium satellite coverage and is compatible with Raymarine Axiom MFD

Services of weather plotters that work with the system Garmin inReach, such as FastSeas, implement a model where users send specific weather requests to companies by email. Having received them, FastSeas replies to the user with a letter that "weighs little" (depending on the length of the route, it can be several mails). Users Mazu, in turn, can download and display GRIB files... “On average, it takes thirty seconds to a minute to send an email and about five minutes to download a mushroom,” says Craig Myers, Product Manager Mazu... - Of course, we are not talking about megabytes or gigabytes in this case. We use compression, so the output is kilobytes to send. "

“For coastal planning, a website is best, Walters continues, adding that the site graphically displays the user as FastSeas calculates the suggested route. - Offshore, everything goes through emailwhere users send an exact request, and we send them back the routing. "

These emails - both from the user to the cloud and vice versa - are measured in several kilobytes. “Cloud plotters are very handy for cruisers,” says Olson of the service. PredictWind... “There’s less data to send, and in that sense, it’s a more efficient way.”

Heavy GRIB files are compressed to kilobytes so that they can be downloaded offshore via satellite communicators

Regardless of who receives the weather data with route calculations and how they do their calculations, today's products are worth getting to know. “Ten years ago, weather plotters were not available,” says Olson, noting that satellite communicators such as Iridium Go or RedPort Optimizer changed the rules of the game in the market. - Yachtsmen-cruisers today can get better weather data and route calculations than participants  Volvo Ocean Race a decade ago. "

Apart from the accuracy of various government and private weather models - the accuracy of which will only improve in the coming years thanks to the emergence of additional satellites and new generation satellites, such as "Eola"sounding wind conditions from the European Space Agency - it should be noted that the only negative of the satellite connection is its price. Although this barrier is not that great. “Even people who walk on a budget like me can afford it,” says Walters, who actively sells on the 28-foot Bristol channel cutter since 1992. Its monthly fee for FastSeas costs $ 5 a month (with an annual subscription; or $ 10 a month with a monthly subscription).

And although weather forecasts and weather route planners are still in error - after all, this is weather - modern technologies and services give an impressive result for mariners, no matter where they are going to use this data.

“Now, being caught in a real bad weather at sea is simply unforgivable,” Olson sums up. And we will add: so be it!

Reading arrows and icons in files GRIB

GRIB files contain a series of circles representing the predicted wind conditions for a given location and time. Empty circle means a quiet wind, and arrows and icons show the estimated wind speed and direction. Long dash icon means a wind of 10 knots, short - 5. For example, a circle with an arrow pointing to the 9 o'clock position with two long dashes on the badge and one short means 25 knots west wind is predicted.

Weather apps for boaters: reading arrows and icons in GRIB files

Author: David Schmidt / Translation: Dmitry Bushuev

07.05.2019