The fixed camera on the stern of Vestas Wind captured the worst possible unintended gybe. That’s when you’re blasting along at 19 knots through a tropical night offshore, and your Volvo Ocean 65 suddenly smashes its way up onto a reef, shearing off the rudders and spinning 180 degrees as the waves and wind take total control.
Of course, the obvious question is: how the heck did professional sailors make this mistake? The fairly large area of reefs and islets is well charted, and is certainly obvious from space. In the screen grab shown above left, taken from a video shot aboard Alvimedica, Vestas Wind (designated as “SART ACTIVE,” actually one of the crew’s PLBs) is on the very steep-to, western side of the reef while Alvimedica (the green boat icon) is on the safer side ready to assist. While I’m not sure exactly what the Volvo navigators saw on their AdrenaPro Offshore and Expedition 9 charting and routing screens, several reported that they had to zoom way in to see the real danger, and Vestas Wind thought the shoal was at least 40 meters deep.
At any rate, Vestas Wind navigator Wouter Verbraak and skipper Chris Nicholson have admitted to a grievous navigation error, and hopefully a lot of sailors will now be extra careful with their electronic chart work. But here’s the thing: I believe that most every charting program, app and MFD “knows” when we’re about to make such a mistake and could warn us! Vector charts are databases of objects and related information, and the algorithms that decide what gets drawn on a screen at any particular location and zoom level are what we need to be careful with, since they can sometimes omit crucial info. However, no matter what a user may see on screen, the software always knows precisely where you’re headed relative to the data—whether or not its being displayed. A constantly running search algorithm that can tell us, “Hey, shoal water and then land one mile dead ahead!” doesn’t seem hard.
In fact, data-based grounding alarms have existed for quite a while. Jeppesen C-Map calls their version Guardian Alarm and any developer who wants their charting software to use C-Map Max or 4D cartography receives an SDK containing the search algorithms. When available—and apparently that includes a lot of current chartplotters produced by the likes of Furuno, Standard Horizon and Humminbird—the MFD user gets to set a minimum draft and the distance to look ahead. They also get to choose what chart objects will be “interrogated,” and the search area is shown on the chart by a red triangle. If a danger is seen, an alarm pops up, and you can also get a report showing what object type triggered the alarm. The Guardian Alarm can only be set to search one mile ahead at max, which is not ideal for a boat doing 19 knots offshore, but it still might have helped (especially if they’d set their draft to 99 feet or whatever that max is). And couldn’t ever-improving processors handle longer ranges?
C-Map’s grounding alarm doesn’t only run when you’re underway, but can be used to check a proposed route. I’m happy to add that Raymarine is working right now to make C-Map 4D cards compatible with all its current displays. I don’t know for sure that Guardian Alarm will be part of Lighthouse II v13, but let’s hope so.
Let’s also note the similar “Look Ahead” function that was prominent on the Maptech i3 over a decade ago, and was also on the sister Sea Ray Navigator, now long gone. The graphic looked something like the Simrad and Echopilot forward-scanning sonar that is gaining a new lease on life, but of course, is quite different in potential range and use. I want both!
Finally, Coastal Explorer can also identify obstacles along a planned route and even guesstimate their names by using the data from vector charts. If it had an underway-grounding alarm it could maybe say, “Hey! Cargados Carajos Shoal five miles or 15 minutes dead ahead!”
So what am I missing here? We all make mistakes. Why aren’t vector-data-based grounding alarms more readily available, and why aren’t they used more when they are available?
As a side note, at press time veteran Volvo Ocean Race navigator and Expedition developer Nick White e-mailed me to say he has decided to enable C-Map Guardian in his racing software, but he’s hoping that no one will use ?this chart-based grounding alarm ?as substitute for the proper ?practice of identifying all dangers ahead.