The wrecking of Volvo Ocean Race crew Team Vestas Wind on remote reef is a reminder of the chief danger of modern electronics - the illusion of faithful accuracy

How is it possible for a yacht bristling with the latest technology to hit a well-known reef, as Volvo Ocean Race crew Team Vestas Wind did, with catastrophic consequences? How can it happen to one of the world’s top navigators?

And if they can make a mistake, as skipper Chris Nicholson has manfully admitted, can we observers really say we wouldn’t make the same one ourselves? Never?

It’s all too easy to see how this might have happened, and anyone who has ever sailed in the poorly charted, reef-scattered tracts of the Pacific or the Indian Oceans can imagine why and how. It would be bad luck and arrogance indeed to sit in judgment and say no, not me, it could never happen to me.

This is not like coastal navigation in Europe. To sail in remote areas of the world is to go back in time, and the disaster of Team Vestas is a collision in more senses than one: a collision of the modern and minutely known world, crawled to centimetres from the deeps of bathymetry to the prying exactitude of Google Streetview, with a surprisingly vast oceanic landscape that remains a best guess estimate.

Despite all the modern technology available this is an old-fashioned shipwreck, such as have splintered ashore in every age and done for countless mariners over the millennia. They found themselves stranded ashore, in a place without habitation, water, food or communications, a predicament straight out of Robinson Crusoe, but with journalists as far away as another galaxy incongruously and futilely clamouring for photos and interviews.

As for why this happened, my guess is almost certainly for the same age-old reason: the crew were sure they were where they were not.

Even today, this is easier than you might think. Modern charting seems so accurate. And so often it is, as when the dot on your chart plotter puts you alongside your very marina berth. This precision makes it surprisingly hard for the brain to shake off the idea of that picture as fact. We can readily accept the idea of a certain margin of inaccuracy, and make routine allowances for it, but half a mile, a mile, five miles?

In many parts of the world, reefs and islands, some like the reef Vestas tore into, are barely rocks awash and well nigh invisible at distance, and they may be a mile or miles from their charted positions. One Pacific atoll is known to be six miles from where it is shown on charts. The information used for charts may still largely be based on leadline surveys from the sailing ship days of the 19th Century.

Satellite imagery has allowed modern hydrographers to work out where many of these islands actually lie, and often an offset is printed on paper charts, though not necessarily reproduced on electronic charts. Many charts of these areas have been corrected to the WGS84 datum, while others have not, and so the position of an island can vary from chart to chart, or at different zoom levels.

With electronic charts there is also the matter of detail at different zoom levels, which can also be seriously deceptive. An island or reef may appear inconsequential at one zoom level, but resolve into a sizeable hazard a single zoom step in. As an example of this, take a look at these two images from the Navionics web app that shows the reef Vestas hit at one zoom level, then in more detail (and substance) in the next.

 

Cargados Carajos Shoals

Cargados Carajos Shoals

Cargados Carajos Shoals, Indian Ocean

Cargados Carajos Shoals, Indian Ocean

 

Accepting that all charts, electronic and paper, represent an approximate picture and not reality requires a mental recalibration on several fronts, particularly at a speed of 19 knots, as Team Vestas was making at the time of the grounding. At this speed the distance of a 1,000m chart inaccuracy would be covered in under two minutes.

This is not the first time a high-profile race yacht has been shipwrecked on a remote reef. In 2010, the Clipper Ventures yacht Cork hit a reef in the Java Sea and foundered. The circumstances were broadly similar, in that the collision happened in the dark, the reef was remote, uninhabited and low lying (too low to produce a strong radar picture), there was no significant change in the soundings, and when the yacht grounded getting the crew off the boat was dangerous in itself.

The reef the Clipper yacht hit, Gosong Mampango, is 1,000m east of its charted position, and an associated reef to the south is two miles to the north-east of where it was charted. The electronic charts did not carry the warning that the paper charts did that the reef was almost a mile east of its charted position.

What we can perhaps learn from the Team Vestas incident, as with the Clipper shipwreck, is simply more caution. A second system of navigation is needed, be it only soundings, to verify GPS positions. A larger margin of error is needed in areas of suspect charts with, as was recommended in the report into the Clipper grounding, different offlying waypoints for daytime and nighttime approaches.

We would all be safer in these places if we felt the instinctive deep fear of reefs that sailors had in years gone by, when landfall was accepted as the most imperilled part of any passage. But how can we arrange to feel it today, when modern navigation equipment has all but expunged dread of the coast and we are all, mostly, hand on heart, more interested in sending emails and routeing options and getting the latest grib weather files?

Despite all the great benefits of GPS, chart errors, scale errors, and sailors’ errors continue to catch out skippers who think they’d never make these mistakes. They catch out cautious cruising skippers and the world’s best navigators alike. If you sail long enough, far enough, mightn’t anyone have a few close shaves?

When we were in Fiji in July researching and filming our current bluewater series, specifically setting out to show the difficulties of navigating in coral and how to go about it (including entering a coral pass and lagoon that was not even shown on our electronic charts, even at the largest scale) we learned that some dozen yachts a year are wrecked on reefs here, even though most of these reefs are reasonably well marked.

Most round the world sailors don’t put all their faith in charts and today many cruising sailors work out the location of reef passes, islands and lagoons by georeferencing Google Earth images and using them in conjunction with electronic charts. (We have a four-page feature on how to do this and where to get the data and images required in our November issue).

But for all that, even brandishing every known source of information, seamanlike reef navigation depends on the very same techniques that were used in all times gone by: the sun overhead and behind you and someone high up in a conning position applying the Mk 1 eyeball to assess what is really beneath and ahead. And the inclination to use every sense, including sound and feel, and to turn back if uncertain. The biggest danger is certainty.

  • Mahatmah

    These guys are professionals, and carry the best equipment. No excuse. Another question though, what coud race control have done. They are tracking the boats continuously?

  • Sugarsail1

    the desire to win often trumps prudent seamanship as well.

  • Jacek Pietraszkiewicz

    And I think that you just have to know which tools to use. GPS ENC are easier, but you need to know how to use them. Very colleague navigator sorry, but I think it’s just his fault.

  • Douglas Perkins

    There are places one can go to get high quality training in the use of electronic charts. It is critical that one be aware of the limitations of whatever system one is using in the course of navigation. I am torn as to what would be the best shortcoming resulting in this incident. Would it be best that their training was inadequate or that there was a lapse in their attention to detail?

  • James Charles Schneider

    I agree with VikingExplorer. The whole set of facts about possible lack of accurate data about the position of the reef still begs the question. If a navigator and captain are doing their job, they are well aware of it and will take it into consideration, such as by setting a depth sounder alarm, AND taking note of the current depth reading as compared with the depth datum of the current position on the electronic chart. Apparently, the energy of the decision-makers was applied to racing, as opposed to navigating. When I was planning my cruise to the Bahamas, after two years of cruising experience, I was aware that the soundings there were taken under sail in the 19th century, and I was hardly a world famous yachtsman.

  • PEPV

    If you properly set up race notes in Expedition (exclusion
    zones), they stand out at any usable zoom level especially if you color them red. Race notes should be set
    up anyway prior to running the optimal routing function so the routing
    won’t take you through land or hazards and determine the optimal route with such obstacles factored in.

  • Mahatmah

    As I see it the arguments of the article are fully acceptable and presented as a defence for the crew of Vestas. Even so, on the reef there is a beakon, as far as I can judge, not far from where the yacht was wrecked. It should have shown on the radar, which you are required to use if you have one. I’m not sure I agree that this was just bad luck.

  • PEPV

    Looks clear to me, “crystal clear”.

  • PEPV

    Sorry, gang, all wrong. If you look at the YouTube video there is a clear shot of their Expedition screen showing their track right into the reef. The information was there, the GPS was accurate, and so was the chart they had loaded on Expedition. This appears to be a case of extreme fatigue leading to a complete lack of situational awareness despite the information being right before them in high definition color.

  • Shane Kennedy

    America offset their GPS system !

  • dodger99

    I agree JK, in the video it is also apparent that something had drawn the attention of the crew off the port beam (probably the light marking the southern tip of the island). It is an easy mistake to make but nethertheless a careless one. A simple depth alarm would have prevented this incident.

  • VikingExplorer

    The whole discussion about GPS accuracy and/or chart accuracy and/or the zoom in problem misses the point. This is a feature about 10 miles by 50 miles. The depth meter should have been configured for an audible alarm for 50 meters or maybe even 100 meters. This should have alerted the crew miles before actually striking land. Take a look at the chart. It goes from 500 to 100 in about 5 miles. How does that not set off an alarm?

  • JK

    I have to disagree about the zoom excuse. The top navionics view clearly shows obstructions and depth contours that would warrant the need to zoom further, especially since they sailed right through the shallowest of those depth contours right where there is two specs of land on that zoom level. They weren’t looking at all. That is the only explanation here.

  • quercus33

    Charts for UK waters are a lot more accurate than in some remoter parts of the world.

  • WanderingBear

    I have to agree, its one of todays modern problems of trusting electronics too much.

    GPS may well be super accurate, but when were the charts drawn up, & with what datum.

    If you are using charts drawn up 50, 60 or even in places more than 100 years ago, then this is your your level of accuracy, not the best electronics money can buy.

    When sailing in Patagonia & Antarctica, we had onboard some electronic charts, mostly paper chats & great big book of charts from the Chilean Navy. There were small differences in the three of them, but in reality, nothing much to worry about.

    The most important thing, and what was really apparent, was where the GPS put us on those charts. Many times while anchored in a quiet bays, our GPS would put our position sometimes several miles inland, somewhere up a mountain!

    The drawing of the coastline & the shapes were usually very accurate, but according to the GPS, they were just not quite in the right place.

    We were lucky in Patagonia, as the high mountains & steep sided shoreline gave a good reflection on the radar, so that the images we saw were in fact “totally real” in regard to where we were regarding the water & land.

    That was the only way to navigate there, together with slowing down, more eyes on deck, and trusting the depth sounder. We got back to basic seamanship, rather than the new world of electronics, as that was what the people who drew the charts did.

    The bottom line was:, We could not to trust our position on charts, because we could not trust the charting.

  • Jack Robinson

    The local shoreline around the North Kent Coast, is full of indentations, mud banks, narrow water ways, that disappear at Low Water, and many other unknowns…having grounded on many occasions in the Medway, and Stangate Creek, it is lucky is only soft mud, and no rocks, so one comes off on a rising tide…glad we do not have any Coral Reefs around these parts…