14 September 2012 - 18:53 • 4923 views

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The Ice Gates are compulsory crossing points for Vendée Globe racers in the southern seas. Their aim is crystal clear: prevent skippers to sail to deep in the South in order to minimize the collision risks with drift ice. Their positions have been defined during a briefing earlier this week but can still be changed.

The 1996-1997 Vendée Globe Edition was something to remember. The death of Gerry Roufs and the shipwrecks of Raphaël Dinelli, Thierry Dubois and Tony Bullimore made the race organisers adopt extra safety measures. The boats’ shapes have changed and the Ice Gates first appeared in the southern seas during the next edition, in 2000-2001. Their aim is very simple: prevent the fleet to sail too close from the Antarctic, which would considerably increase the collision risk with icebergs or growlers.


There’s nothing too complicated about how these gates work. An Ice Gate is a segment on a given latitude, defined between two longitudes. The space between the longitudes is around 400 miles, the equivalent of one and a half day of sailing. There are four to six, or sometimes seven gates along the route and they are spaced out between 800 and 2,000 miles. In order to validate their crossing, skippers only need to sail through the gate from north to south, from south to north, or just keeping sailing north.


How to determine the gates position?


To determine the gates position, the Vendée Globe Organisation works in tight collaboration with CLS (Collecte Localisation Satellite), a French agency whose work consists in following boats, turtles and cetaceans… and of course ice. “The CLS role is two-fold. We work with them to know where the ice is and also to determine where we’ll put the gates. They’re an essential operator for us”, said Denis Horeau, the race director.


The collaboration with CLS organises as follows: “We establish a working plan with them for the ice monitoring, and they place an order with Canadian and European operators running the satellites for a number of organisations. Thanks to various technologies, they will try not only to find out where the ice is but also to see where they drift. Thanks to the weather softwares and drift algorithms they are using, we will certainly be able to determine where the ice seen on Monday will be on Wednesday and then on Friday”. Besides, “CLS will assign an engineer on the Paris race HQ, who will be part of our team for the whole southern seas period”, adds Denis Horeau.


Their position can change


The position of these gates is not fixed. A pre-positioning has been determined on September 10 and 11 but it “will change according to the satellites reality, after start day”, Denis Horeau explains. The position of a gate can be modified before the first skipper of the fleet reaches the previous gate. “Once a skipper is at a gate, the next one is fixed for all the other skippers”, says Denis Horeau.


The Ices Gates are not the only mandatory crossing points for Vendée Globe sailors. The Australian authorities have also required that some gates be put in place off their coasts. “The Australians intervened many times on the Vendée Globe to rescue skippers and then they asked us not to sail too far from their coasts”, said Denis Horeau. Whatever their function may be, all of these gates have a common goal: keep the skippers as safe as possible.