Credit : Yann Riou
The big speeds are now a thing of the past: the front has stalled some 500 miles from Portugal with its progress curtailed by a long ridge of high pressure between Brittany and the Canaries. The depression which has deepened behind the fleet, is rolling in on itself, leaving a southerly breeze in its wake, which is gradually dying out from 18°W, to be a replaced by a northerly tradewind system along the coast of Lusitania. Fortunately this very extensive barrier appears to be fairly narrow offshore of the Iberian peninsula, but these one hundred miles or so within the system aren't going to be easy to negotiate...
Traversing the high pressure zone...
Basically, this zone of high pressure is in the process of splitting into two sections: one cell in the Bay of Biscay and another offshore of Madeira. As such, the col between the two plateaux of high pressure will create a barometric marshland, where non-existent to light winds will considerably slow the progress of the fleet. And it's the position of the minima which is very important for the navigators: at this point, the wind shift from the south to the north will be the clearest, even though it will still be necessary to await a succession of fits and starts at the mercy of the gusts. For now opinion is split since Groupama 4 is aiming for Peniche (50 miles to the North of the entrance to the Tagus) whilst the Emirati leader is diving towards Porto (100 miles further North).
As a result, Franck Cammas and his men have the heavy burden, after their spectacular comeback to snatch second place, to be leading the way for those on a southerly option, since her two pursuers are in her wake (Telefonica and Camper). Groupama 4 seems to be opting for the most direct route, though it's unclear what is in store for them, whilst Abu Dhabi, accompanied by Puma (around thirty miles further North), seems to be anticipating a gradual easing of the wind. As such, this option would be more effective for being able to luff up to maintain speed, but there is further distance to travel...
Siphoning the breeze
The average speeds of over twenty knots are already a done deal: the breeze this Wednesday morning had already dropped to around fifteen knots this lunchtime and it will continue to fall to around ten knots from sunset, before fading to less than five knots at midnight! It's going to be an action-packed night then, though their way will be lit by the moon on flat seas. As a result, the leaders will lose their advantage over the next twelve hours, but it remains to be seen whether or not they'll be able to hang onto their current positions or if they'll be overtaken to the right or left.
Indeed it's on the journey across the barometric col that the hierarchy for this seventh leg will be decided, and the outcome is highly important for the final standing. By shrinking in on themselves, the two zones of high pressure will form a very interesting isobaric curve to get around the zones of calm, since the wind, though light, will slowly shift to the North where it will gradually build the closer the boats get to Portugal. In this way, it will be necessary to follow this 'siphon' around so as to extract oneself from this uncertain area as quickly as possible. However, this doesn't mean that victory is guaranteed for the first boat to escape the marshland: even if there is still very little separating the crews, there will be some zones of calm yet to negotiate as the crews make their way up the Tagus River from Cascais to Lisbon... Will Franck Cammas and his men finally take leave of their rivals after ten intense days of racing across the Atlantic Ocean? Now isn't the time to break into a swansong...
Position of the competitors in the Volvo Ocean Race on the seventh leg from Miami - Lisbon at 1300 UTC on 30/05/2012
1. Abu Dhabi Ocean Racing - 374.7 miles from the finish
2. Groupama 4 - 13.6 miles astern of the leader
3. Puma - 13.9 miles astern of the leader
4. Telefonica - 28.7 miles astern of the leader
5. Camper - 30.7 miles astern of the leader
6. Team Sanya - 49.2 miles astern of the leader
Read more: http://www.skipperondeck.gr/index.php/news/308-vor-2012-7c-swan-neck.html