CORK CLIPPER AND VESTAS VOLVO OCEAN RACE INCIDENTS
Two significant incidents in recent news have shown the difficulties presented by purely using electronic charts for passage planning and both were the product of the same error. On 9 November 2014 the 65ft Team Vestas Wind, a competitor in the roundthe-world Volvo Ocean Race, was 10 days out from Cape Town heading north towards Abu Dhabi. She was on a threesail reach in a true wind of 14-16 knots, 10° aft of the port beam. Boatspeed was averaging 16 knots with bursts of 21 knots. Shortly after 1900 she emerged from a rain squall. It was dark, the half moon high in the sky astern was intermittently masked by cloud. Suddenly there was a sharp crack, a daggerboard had broken. Rocks were sighted to starboard and immediately an attempt was made to furl the code zero and No. 3 genoa to depower the boat. The bulb keel, which was canted to port, caught on a rock pinnacle and she swung sharply to port, eventually onto a southeasterly heading, hard aground. All nine people on board escaped serious injury but she was very badly damaged, high and not quite dry on the Cargados Carajos Shoals, a hazard of which disastrously the skipper, navigator and the rest of the crew had been totally unaware. The skipper and navigator had discussed the shoals but this was probably based on the zoomed-out chart, from which they deduced that the shallowest water was a seamount over which there might be some change in sea state but which was in no sense a navigational hazard. The C-map chart shows only that a larger scale chart is available within the rectangle around the shoal. Had they consulted the Admiralty small-scale paper chart they carried, or zoomed the C-map chart in to the same scale, there would have been little chance of missing the significance of the hazard. In 2010 during the Clipper Around the World Race, the 68ft Cork Clipper grounded on a remote island in Indonesia and was subsequently lost. A post-race inquiry revealed that the digital chart being used on board Cork Clipper, although up to date, lacked the warnings found on the paper charts for the region. These warnings indicated that directly transferring latitude-longitude positions derived from GPS to the charts might result in significant error because the chart was not consistent with the WGS84 datum. Because the digital chart was inconsistent with a Gps-based latitude and longitude, the boat’s electronically plotted position showed the boat safely clear of any obstructions.