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How to Have the Most Accurate Nautical Charts

A Navionics chart shows the Chatham (Massachusetts) breakthrough with bathymetric contours as it appears on a Raymarine chartplotter.

A Navionics chart shows the Chatham (Massachusetts) breakthrough with bathymetric contours as it appears on a Raymarine chartplotter.

Social Studies

In these days of oversharing, boaters now have a way to get the best, most up-to-date charts by joining the “in” crowd.

Boaters have been sharing information since long before a couple of vikings discussed the best route across the bay to get to the next town ripe for pillaging. In fact boaters have seemingly always had a good social attitude: Take some good information and a like-minded soul, and give as good as you get.

As with most everything in the Information Age, the methods we use to share data have only gotten better—if they’ve become a bit impersonal—as electronic charts and web-based cruising guides have come to the fore. Up to now, the best examples of these resources have improved dramatically as mobile computing and smartphones have taken off. is a web-based community that provides updated information via its broad, experienced member base. Updated mostly through its Web site, the information is displayed through many apps and PC-based charting programs such as MaxSea Time Zero, Rose Point Coastal Explorer, Nobeltec, and others. Garmin’s Bluechart Mobile app also incorporates data as does its PC-based Homeport voyage-planning software.

Navionics Community Edits are created using the mobile apps on phones or tablets. Users mark hazards, new navaids, anchorages, and more through the app itself, and most users view those changes on the app, through a layer added to the chart with the collective data added to it. Electronics manufacturers Raymarine and Navico (maker of Simrad, Lowrance, and B&G brands) have generally both allowed the Community Edits to be viewed on their chartplotters via chart-card updates using a PC.

Whose Data Is It, Anyway?

For all this sharing of information and data one must ask: Who actually owns the data? The answer is, you do. But think of it as owning a diamond mine or a repository of natural gas on your property. You may own it, but you personally don’t have the means of deriving anything of value from it. Instead you must choose one of the systems to get the value—in this case, readable, useful charts—out of it. “People put a lot of time, effort, and money into the boats and capturing this data,” says Shane Coloney, product manager for content and cartography for Navico. “There are uses of that data that we need in order to provide the services back to the user. So when they share that data with us, and choose to make it public, we need rights to that data, so that we can incorporate it and provide it in that public manner.”

It seems as though the community charting services agree: “What we provide is a service that then takes what is otherwise unusable data to them, run it through our own proprietary software and then gives back a subscription service that gives it better results that are usable for them,” says Shaun Ruge, global product manager for Navionics. “It’s a tradeoff and we need some rights to the data just to be able to provide the service,” says Coloney. “But ultimately it’s the users’ data.”

But more recently it’s not so much you as your chartplotter that’s become the social butterfly. Particularly if you are a subscriber to such programs as Navionics SonarCharts. Users record data logs through the program’s SonarCharts program as their plotter and GPS work together to map the bottom beneath the transducer wherever an equipped boat roams. Then the charts are uploaded and subscribers to the service are able to access the SonarCharts, which include a combination of all contributors’ sounding data.

When the program went live, many wondered if such personal, “proprietary” details such as the secret honey holes of fishermen could be a stumbling block to true community sharing? 

“All these things users thought were secret just simply aren’t, because there’s a million other people fishing and they’re doing the same things,” says Shaun Ruge, global product manager for Navionics. “And now that the concept of contributing to a community is not foreign anymore, especially if you look at social media, forums and all of that. I think people are drawing those conclusions and realizing that leveraging the community gives you so much more useful information and location-based information than you could ever previously get. We still get resistance and there will forever be resistance to those types of things. The tinfoil hats will eventually go away, and mapping will become more and more based on information we all provide.”

Simrad and the Navico brands also provide users with a program that logs their soundings and creates their own individual charts using their own data called Insight Genesis. Begun in November 2012, it has just undergone a major shift: “We’ve just launched Insight Genesis Social Map, which is taking Genesis to the next step,” says Shane Coloney, product manager for content and cartography for Navico. “We have all these users who are generating content of their own, but now we’re giving them a platform to share that information with the broader user community. So now they’ll have an option of sharing that data with the community and being able to see all the data that the entire community has generated. So not just their own trips but all that data that the community is making.” 

Users will be able to see their own information, and of course those sportfishermen can still have their secret spots, which will be shown in intricate detail due simply to the amount of time they spend pinging them. Understandable that those fishing customers may not want data to be public. But cruisers getting ready to go to an area they’ve never been before may want to share that data and benefit from the data that’s being collected by others. Like any community, it starts with the individual user.

That individual user is the centerpiece of the Humminbird Autochart system, which allows a user to create a chart right on their boat’s system, with no subscriber service or sonar-log uploading. It requires little more than a one-time purchase of the Zero Lines Map card that contains the software and functionality.

“Customers who buy the C-MAP Max-N or Max-N+ products, which are the format for Lowrance, B&G and Simrad, can collect their pings and they can upload that and create contour data,” says Ken Cirillo, a business development executive at Jeppesen, parent company to C-MAP. “And then if they opt in to allow that data to be shared it goes into a common database, and we are able to take that data and access that data and add that data to our high-res bathymetric database that we have as a separate product.”


One interesting new feature, available on Furuno, Raymarine, and Navico products, is a view of multiple charts simultaneously. A split-screen view allows a side-by-side comparison of two kinds of chart data, which may offer confirmation of safest routes, or introduce insight in questionable ones. That’s good because SonarCharts and Insight Genesis charts only show soundings, not the navaids and other data contained on regular navigation charts.

Another factor to consider, Navionics has a new version of Plotter Sync that allows a Web-connected iPad to download fresh data, and then, when carried aboard, upload it to a compatible wi-fi-enabled Raymarine MFD. Sonar logs can go easily back to Navionics in the reverse direction. This automated system could change the game, taking the effort out of moving chart cards to benefit from the crowdsourced charting layers, letting even the most antisocial among us benefit from the data without lifting a finger.

This article originally appeared in the August 2014 issue of Power & Motoryacht magazine.