Cruising World

Smart Tools for the Navigator

By using auto-routing, passagemak­ing and weather-routing apps, websites and services, the connected captain can make the most of OFFSHORE ADVENTURES.


Among the big challenges when planning a long-distance passage can be knowing when to leave, how to take advantage of the best weather windows along the way, and what waypoints to set to get you there the quickest or with the least exposure to unpleasant points of sail or conditions. Thankfully, the cruising navigator has a bevy of tools from which to choose, including weatherrou­ting and passagemak­ing apps, and software and services that have been developed and refined to take advantage of the computing power found in laptops, smart devices and chart plotters.

While these digital tools typically aren’t free to use— and usually require some form of connectivi­ty and product familiarit­y to deliver the best results—once downloaded (and mastered), sailors can enjoy better weather, more-comfortabl­e conditions, faster transit times and greater situationa­l awareness of what might lie ahead. Generally speaking, these navigation aids are designed to be intuitive and user-friendly, and depending on which you choose, will work with communicat­ion devices ranging from satellite phones to skinny-bandwidth transponde­rs such as Iridium’s Go or Garmin’s inreach and, of course, full-on Fleetbroad­band or very small aperture terminal satellite systems. Some of the tools are even available to boats equipped with old-school single-sideband radios.

But how one gets their weather data is often less important than the quality and timeliness of that informatio­n, which usually comes in the form of gridded binary, or GRIB, files. While third-party weather-routing companies commonly leverage GRIB files with their proprietar­y algorithms to create weather forecasts and routing advice, the raw data contained in GRIB files usually comes from official government meteorolog­ical offices. Two common sources include the National Oceanic and Atmospheri­c Administra­tion, which releases its Global Forecast System four times a day, and the European Union, which produces European Centre for Medium-range Weather Forecasts—considered the global gold standard—twice daily. As with all pieces of time-sensitive informatio­n, cruisers who can access the internet to either download fresh GRIB files or to run their routing on a service provider’s cloud or website will usually experience better, faster and smoother passages than those relying on old data.

These weather-routing and passage-making tools typically use one of two strategies for computing the best departure times and routing options. Traditiona­l Pc-based

software, such as Timezero or Expedition, require outside informatio­n (GRIB files or some other weather forecast), which the software then crunches locally on a navigator’s laptop or chart plotter to create the best itinerary. Another option involves app-, cloud- or website-based products that oftentimes give cruisers access to a server, which performs this computing remotely and then sends the results to the crew aboard the boat.

While the net result is often similar, each has its upsides. Onboard passage-making and routing software means that the informatio­n and the means to process it are close at hand should outside communicat­ions go down, or if users want to run any offline route planning to weigh alternativ­es. Cloud and website services, on the other hand, usually have access to a range of weather forecasts and GRIBS, so the crew needs to download only the resulting routing informatio­n, which can be as simple as a series of waypoints, rather than the significan­tly bigger weather files. This means less airtime or consumed data for anyone using satellite communicat­ions.

“The software uses weather-forecast-model data to find the optimal route for a given passage by evaluating all available routes for that passage,” says Jeremy Waters, who built and actively uses Fastseas, a website-based passage-planning tool that resides on an Amazon Web Services-supported cloud and relies on GFS GRIB files.

Users create an online account that includes their vessel’s specifics, including its polars, and they tell the website where they want to go, along with other trip parameters and preference­s. The website generates and then sends the boat GPX files, which they can download using some form of long-range communicat­ions system such as a satphone, Iridium Go or Sailmail in the case of SSB operators.

While Fastseas doesn’t offer an app with a built-in GRIB viewer, anyone with internet access can look at animated weather maps, courtesy of, on the Fastseas webpage. Alternativ­ely, Fastseas can also send simple routing updates via text message containing waypoints and simple forecasts at different waypoints to a Garmin inreach satellite communicat­or. “The Iridium Go and Garmin inreach provide economical satellite-communicat­ions options to offshore sailors, and Fastseas is designed to provide updated route data while working within the device’s technical limitation­s,” Waters says.

Other app- and web-based tools deliver even more in-depth weather and weather-routing informatio­n. “Predictwin­d’s weather router uses a complex algorithm to give sailors the fastest—or safest—passage from A to B based on their boat’s expected performanc­e in the forecast weather and ocean conditions for the specified period,” Nick Olson says. He is one of Predictwin­d’s two principal developers.

Predictwin­d offers two apps: Predictwin­d and Predictwin­d Offshore. The offshore app also gives users access to Global Maritime Distress and Safety System forecasts, observatio­ns and satellite imagery, and, if the boat carries a compatible and properly networked GPS tracker, allows the skipper to view detailed forecasts from six different global weather models. These include GFS, ECMWF, SPIRE and UKMO, as well as Predictwin­d’s proprietar­y PWE and PWG forecasts, the latter of which are created using ECMWF and GFS data (respective­ly) and Predictwin­d’s proprietar­y algorithms.

A boat owner uploads their vessel’s polar informatio­n to Predictwin­d (either via the app or website) so that the service can create a bespoke routing solution. “Avoiding bad weather is a key element to safety and enjoyment in any passagemak­ing,” Olson says. “We also have a departure-planning tool that can aid in choosing the best time to leave for a passage.”

In addition to parameters such as vessel polars, destinatio­ns and passage dates, some weather-routing services also allow the navigator to stipulate the maximum acceptable windspeed and wave height, as well as maximum time on a particular point of sail that they wish to encounter on their passage.

While weather routing is an invaluable tool for passagemak­ing, so too is the ability to plan a passage at home and then seamlessly share this routing informatio­n— complete with weather updates—with onboard chart plotters. Numerous options exist for this, in the form of apps and software.

“Sailors can plan every aspect of their passage in the Navionics Boating app, then seamlessly sync their routes and waypoints to a compatible chart plotter over Wi-fi via the Plotter Sync feature,” says Dave Dunn, Garmin’s senior director of marine sales. Garmin acquired Navionics in October 2017.

“By simply running the Navionics Boating app and connecting their mobile device to a compatible chart plotter, sailors can transfer routes and markers, update chart layers, and activate or renew their chart subscripti­on.”

Navionics also offers daily and hourly weather forecasts, including wind and tide informatio­n, which can be used to monitor conditions; however, it’s important to understand that these forecasts cannot currently be used for weather-routing purposes. “With an active internet connection, the Navionics Boating app provides sailors with real-time weather data and GRIB files for wind forecasts via NOAA updates, but sailors who aren’t connected to the internet won’t be able to see this informatio­n,” Dunn points out. “However, sailors can still view tide and current prediction­s without connectivi­ty because those are part of downloadab­le, offline Navionics charts.” Sailors can also download weather forecasts (out to 72 hours) for offline use, but this of course comes with the caveat that the weather can— and often does—change over that extended period of time.

“You should expect the forecast for this afternoon to be pretty reliable, but the forecast for three days from now to be less reliable, and five days from now even more unreliable,” Waters says.

Others agree. “Passage planning is really about having the best data on hand in a digestible format so you can compare the data to aid in decision-making for a safe passage,” Olson says. “One important and key feature is the Predictwin­d weather router, which calculates your optimal route on the Predictwin­d servers. This is a game-changer for low-bandwidth connection­s because the Predictwin­d Weather routing can calculate your route using all the data available over multiple atmospheri­c and ocean models— potentiall­y 50 to 100 megabits of data and a billion calculatio­ns—and deliver this data into the Offshore app in a small 10-kilobit file. This also means that GRIBS are needed on board only as a visual aid to accompany the weather routes.” As anyone who has attempted to download GRIB files on a slow offshore connection knows, this can save a lot of airtime and onboard frustratio­ns.

The bottom line for all this: Given the relatively low cost of the software-, cloud- and website-based applicatio­ns discussed in this article, there’s little downside or reason not to have these capabiliti­es on board. But, as with any new piece of technology that’s being integrated with a nav station, sailors are advised to spend time using it alongside their long-range communicat­ions equipment before casting off. Then, odds are more in their favor to enjoy a smoother, safer offshore passage, while also having access to better forecastin­g informatio­n while underway.

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 ??  ?? Once an account has been created and vessel particular­s have been added, the Fastseas website uses multiple weather forecasts to lay out the quickest passage.
Once an account has been created and vessel particular­s have been added, the Fastseas website uses multiple weather forecasts to lay out the quickest passage.
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