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Reflections on one of the most dramatic accidents in the history of the Volvo around-the-world race, and what it teaches recreational boaters.
How did one of the most advanced racing yachts in the world hit a reef? One possibility may lie in the level of detail present on their chart when zoomed out fairly wide. A closer inspection of the dramatic shallowing shown in the chart would have revealed the reef clearly. (Photo: Brian Carlin/Team Vestas Wind /Volvo Ocean Race)
Far out in the Indian Ocean, during the early hours of November 30, 2014, the 65-foot sailboat Team Vestas Wind was flying along at 19 knots, with a tropical depression to the southeast and six Volvo Ocean Race competitors in the area. The nine-man crew was sailing one of the most high-tech yachts on the planet, with roughly 11,000 miles behind it on its race around the world. Suddenly, about 216 nautical miles north-northeast of Mauritius, having noticed no hazards on their electronic charts, Vestas Wind smashed hard aground on the Cargados Carajos Shoals. While experts conduct the formal investigation and armchair navigators speculate on the cause of the accident, many boaters wonder: If this can happen to a professional crew with all the latest electronics, could it happen to me?
Accidents Like This Can and Do Happen Closer To Home
Repeatedly, boaters within the well-traveled waters of the ICW, the many tributaries along the East Coast, and the waters of the West Coast, run aground or hit obstructions. Sometimes these are known and charted, sometimes not. Insights from ocean navigators, hydrographers, interviews with the crew of Vestas Wind, and with a member of the accident-investigation team, give us six points to keep in mind when we think about our own navigation practices:
Use up-to-date charts:
When looking at your charts, chartplotter, or electronic navigation apps, do you know if you're using the most current version? NOAA constantly reviews the nation's thousands of charts, and updates an average of 150 charts each week. While some conscientious boaters may update their navigation tools annually, chart suppliers admit that most recreational boaters don't. Without the latest charts, you're missing out on important information, especially in areas prone to shoaling. Although we can view charts online, there are a number of barriers to getting the most up-to-date electronic charts on board, including chartplotters that must be physically removed from the boat, and the high price of annual updates. Many chartplotters can be updated by purchasing and installing new chips or memory devices when available. But these may not contain the very latest changes, and one must remember to do it. We've become so accustomed to getting reminders that new app updates are available for our phones and devices that it's easy to forget that many electronic devices don't offer those reminders. The ideal option is to have a connected product that notifies you when a newer (updated) version of your chart is available. Or, when upgrading your electronics, choose one of the new multi-function display units that allows instant and automatic updates via a WiFi or Bluetooth link.
Keeping your charts updated is good seamanship, but some skippers don't realize just how far off old charts can be. Above, the red lines mark the shoreline on the previous version of this chart. After updating by NOAA, the shoreline was corrected by an average of 10 meters — more than a boat length for many of us. Given that a modern GPS can mark your position within the same 10 meter error, cutting it too close to an obstruction or shore at night or in fog could end badly.
Consider the source/date of your chart data:
If you boat in areas outside major shipping routes, chances are the last time a survey ship took soundings of your waters was decades ago. (To find out when an area was last surveyed, view the Source Diagram inset on your chart.) It's likely that even if you're using a chart updated in the last year, the most current soundings recorded could be from the 1950s or 1960s. In 2010, NOAA's Hydrographic Services Review Panel noted a 100-year backlog in the nation's surveying needs. This means it would take 100 years of surveying at the current pace to adequately survey the U.S. waters used for commercial and military purposes.
Considering the surveying backlog, in recent years there's been a push for the incorporation of crowd-sourced data to supplement outdated soundings with more current reports as well as to give us other value-added content, such as services, port information, and changes to aids to navigation. On the plus side, crowd-sourced data can provide valuable new information in areas not surveyed frequently (areas deemed less navigationally significant). But issues of quality assurance, calibration, clutter, and iability make many professionals in the charting community wary of crowd sourcing.
Beware the implications of chart scale:
Chart scale impacts the level of detail that can be shown on a chart. In the case of the Vestas Wind grounding, the smaller-scale e-chart (1:1,000,000) showed water depths of approximately 40 meters, with no indication of a reef or other obstruction to navigation. However, the larger-scale e-chart (with a more zoomed-in scale of 1:75,000) clearly showed the reef, and so does the paper chart of that region of the ocean. If using only that smaller-scale e-chart, how would you be alerted that there is more detail of a hazard available that should be explored? This concern was voiced by Vestas Wind skipper Chris Nicholson. Even Charles Caudrelier, skipper of Dongfeng, one of the other boats that had previously come close to the shoal in daylight, said, "To see the reef on our electronic charts, you have to zoom right in on top of it. But how and why would you zoom in to it if you don't know [the hazard] was there in the first place?"
Notice anything missing? Charts can't show you what they do not include.The two charts above are of the exact same location, but the one on the left stops at the Canadian border. It's up to you to know what charts are loaded, and, if international boundaries are involved, what might be missing.
There are challenges to e-charting. Cartographers need to draw attention to areas where more detailed information is available and hazards to navigation exist without cluttering up a chart with too much detail (so it becomes difficult to read) or going with less detail for readability but potentially leaving out important data. It's hard to get it right. NOAA's move from paper raster charts toward electronic vector charts provides increased opportunity to improve in this area because vector charts can provide multiple layers of detailed information. But no matter the advances in e-charting, the Vestas episode is a stunning reminder that we should never overlook the importance of basic navigation principles as well as the value of piloting guides and similar tools, which usually alert you to a hazard in the area. (See sidebar to learn the differences between vector and raster charts.)
Understand how to use seamless chart products:
Seamless charts "quilt" together on your electronic monitor, allowing you to navigate smoothly over large areas without having to search for the next chart or deal with clumsy edges. But with seamless chart products, sometimes the scale of the adjacent charts, or the date of the source data from one chart to another, can differ. A boater can go from a high-resolution chart to a lower-resolution chart, or from a newer chart to an older chart, without realizing they've lost detail or lost reliability of the data. Experts recommend turning on chart boundaries in your navigation program, which will help you to see when you're moving from one chart to another.
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"Fly your route" on high zoom:
One of the accident investigators said, "The charts of the world should keep you off the bricks of the world." Almost every chart plotter can be programed to sound alarms when certain rules, of either depth or location, are violated. Boaters with experience on long passages recommend "flying your route" at high zoom, meaning checking the large-scale (more detailed) charts of your proposed route and marking all the features of interest and hazards, and then setting appropriate alarms before reaching those hazards.
Look, listen, and feel:
Pay attention to the real world around you. Today's navigator must digest hydrographic information, AIS, radar, weather data, and many other types of information. Experienced mariners emphasize "situational awareness" — the ability of the skipper and navigator to sort through all the information and determine the most relevant pieces for that moment in time. It's critical not to be lulled into a false sense of security, thinking that what we see on the screen is exactly right or is all there is to see.
Local electronic charts can have significant discrepancies between the location of indicated targets (buoys, reefs, channels, obstructions, breakwaters, piers) and where our GPS puts us on that e-chart in relation to those targets. Sometimes the two don't jive accurately. Dangers lie in the differences, so never cut things close, especially in waning light. Even in the electronic age, it's smart to double-check yourself with real visuals, with paper plotting, and always use the most detailed (largest-scale) version of the chart for where you are and where you're going.
Raster Vs Vector Charts
Raster navigation charts (RNC) (below) are simply a digital image of a traditional paper chart. They have the same look as a paper chart but can be viewed on computers and used by navigation systems and apps. All the information that appears on a paper chart also appears on the RNC, which has advantages and disadvantages. Some boaters want to see all the information presented, but to others this can seem cluttered. While you can zoom on an RNC, as you zoom in, you lose sharpness of the image.
Ballard Harbor, near Seattle. A raster chart (top) shows all the information all the time. A vector chart (above) allows you to declutter and zoom in, so you can focus on the info you need.
Vector electronic navigation charts (ENC) (above) are produced from a vector database of features, and look different from a traditional paper chart. Changes in depth may be displayed with different colors instead of soundings, and there often are fewer land features displayed. An ENC does not display all data at all levels of zoom. This presents a cleaner, less cluttered view. As you zoom in, the information changes, often getting more detailed; it doesn't just get larger. ENCs can have layers of information that can be turned on and off — such as information on marina services — creating a dynamic experience.
RNCs and ENCs are equally accurate and reliable. Many software programs include both, but some use one or the other exclusively. Choosing what's best for you often comes down to personal preference. Do you prefer the comfort and familiarity of a traditional paper chart, with all the data in one view? Or do you prefer a cleaner view, with the ability to zoom in to larger scale charts and other information layers? Both RNCs and ENCs can be viewed and downloaded free from www.charts.noaa.gov (click on Graphical Catalog). Take a look at both types for some of your favorite boating spots and you'll get a feel for the differences in how the data is displayed.
The Fate of Vestas Wind?
"It's clear that human error is responsible for the shipwreck," admitted Vestas Wind skipper Chris Nicholson. Remarkably, after their grounding, injuries to his crew were minor, and the boat was eventually removed from the sensitive shoal in an admirable show of environmental concern, repaired, and at press time was planning to rejoin the Volvo Ocean Race. Meanwhile, the navigator has been replaced.