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2017-18赛季沃尔沃环球帆船赛-LEG 2 Lisbon - Cape Town


Leg 2 Strategic Review. The south pays... again. The second leg of the Volvo Ocean Race 2017-18 ended with a fine win for Spanish team MAPFRE.


Text by Mark Chisnell


The win came after a smart decision by skipper Xabi Fernández and his navigator Joan Vila to commit to the south as they went around the South Atlantic High, playing the hand out to grab a lead they could defend all the way to the line.?


The move


Let’s go back to the morning of the 18th November in Image 1; 04:46UTC to be exact.



Image 1 - ?Geovoile


Dongfeng Race Team (red) have been leading the fleet for over a week, shadowed constantly by MAPFRE (white). But now, MAPFRE and Team AkzoNobel (purple) have gybed to starboard, splitting from Dongfeng. Vestas 11th Hour Racing and Team Brunel had both spent about three hours on starboard the previous morning, but otherwise, the whole fleet had been on port since a gybe way back north of the Cape Verde Islands nine day previously – so they’d all had plenty of time to think about this move.


The strategy


We covered the strategy for this part of the race in some detail in the third of our?Leg 2 Strategic Reviews?so I will keep it short and sweet here.


The trade winds and the Doldrums are both climate zones (a concept that’s covered in more detail in the?leg preview)?– briefly, the earth’s oceanic climate features distinct bands, lying horizontally and looping the globe, running out from the Equator to the Poles in a mirror image. The fundamental idea of these strategic reviews is that the race is won and lost in the transitions between these zones, and that’s exactly what happened here.


South Atlantic High


At the moment of the gybe in Image 1, the fleet were moving out of the influence of the north-easterly trade winds, and into the northerly winds in the western quadrant of the South Atlantic High – an area of semi-stationary high pressure that often stretches across most of the South Atlantic.


In the centre of this high pressure there is very little wind, creating a road block to Cape Town. It’s clearly visible as the blue area to the east of the fleet in Image 2, taken from later the same day, 19:00UTC on the 18th November.



Image 2 -??Geovoile


The anti-clockwise rotation of the wind that defines a high pressure in the southern hemisphere is also visible (it goes the other way in the northern hemisphere).


The traditional route from here is to continue south, skirting the high pressure until the boat reaches the next climate zone, the Westerly Storm Track, to meet a low pressure system moving from west to east as it circulates the Antarctic. The boats will pick up the new fresh breeze from the low and ride that wind all the way to the finish line.

First principles


However, as you can see from Image 2, things were not that simple this year, with another area of high pressure to the south of the fleet, blocking the direct route to the Westerly Storm Track. Nevertheless, Joan Vila and MAPFRE were about to prove that sticking to first principles – lead the fleet south – would still be a race winning strategy.


Let’s zoom in on the moment depicted in Image 2, 19:00UTC on the 18th November, to get Image 3.


Image 3 -??Geovoile


Everyone has now gybed, all following MAPFRE to the south, and it’s clear that the boats to the east are already getting punished for getting too close to the centre of the high and the light winds. We can see the tracks of Team Sun Hung Kai and Turn the Tide on Plastic as they gybed back and forth in their attempts to escape the encroaching light air.

Slow to gybe


So it was a surprise then that the leader and pace setter for the previous week, Dongfeng Race Team should hold on to the port gybe until about 07:30UTC. It was only three or four hours longer than MAPFRE, but it was enough for the Spanish team to end up about 90 miles to the south-west of the Chinese.


MAPFRE have much better conditions and speed at this point; 16.8 knots of wind, and 17.8 knots of speed versus 12.2 knots of wind speed and 12.0 knots of boat speed for Dongfeng. This is because they are further from the light air in the high pressure zone.


Fast forward five hours to midnight on the 18th in Image 4, and the fleet has started to gybe back.


Image 4 -??Geovoile


MAPFRE is one of the last to go, and as they gybe to head east for Cape Town they are almost directly on the bow of Dongfeng Race Team – who by now have clearly recognised their mistake and are trying to get further south to correct the error.


The image tells the story


The story is told in the numbers and the picture – after all, if Dongfeng Race Team had gybed at this point they would still have been closer to Cape Town, and were theoretically ahead of MAPFRE. The leaderboard (which is scoring purely on a boat’s closeness to the finish line) has Dongfeng Race Team in fifth, and MAPFRE 25 miles behind them in last place...


The real story is in the continued difference in wind speeds (18.5 knots for MAPFRE and just 13.2 knots for Dongfeng), and the positions of the blue, windless, high pressure zones depicted in the image. There is the big one to the north-east of the fleet, but there’s also a second bubble of high pressure just to the east of MAPFRE, and this is the one that Joan Vila is focused on getting around cleanly, so they can pick up the low pressure system and front that is to their south.


Let’s go forward another five and a half hours to 05:30UTC on the 19th November in Image 5, and we can now see the big breeze to the south-west of MAPFRE more clearly.


Image 5 -??Geovoile


Their course is taking them south of the little bubble of high pressure and light winds to their east, while to their north, Dongfeng Race Team, Team Brunel and Vestas 11th Hour Racing are all pointing straight at the danger zone.

Convergence


So it was no surprise to find that 18 hours later – at 00:30UTC on the 20th November in Image 6 – those latter three boats have all been forced to take another hitch to the south to dodge the light air and get into the breeze from the front.


Image 6 -??Geovoile


This is now roaring into play, big breeze coming on, pushing everyone east and sweeping away the remnants of the high. To get to this wind the immediate chasing pack have been forced to converge on MAPFRE’s course, and have mostly dropped in behind her. The leaderboard now reflects the reality on the race track, with MAPFRE in front of Team Brunel by 22 miles, with Vestas 11th Hour Racing and Dongfeng Race Team a further 20 or so miles behind them. South paid, and some – and while the different areas of high pressure made it more complex than ‘normal’, the fundamental principle of being first into the wind from a low pressure system still held true.


Dropped?


In the previous strategic review we were concerned that the front would now either move ahead of the fleet, dropping them into the high pressure lurking to the west; or fizzle out before Cape Town, and leave the fleet trying to deal with another high pressure zone setting up before the finish. Any boat that was dropped by the front would have to gybe south to find new wind, but the safest strategy for MAPFRE and the immediate pack chasing her was to keep the hammer down and try to hold onto the front for as long as possible...


And they did just that, not without some difficulty, as we can see from Image 7 at 03:00UTC on the 23rd November.


Image 7 -??Geovoile


Everyone has had to gybe, as the front finally started to move away from them to the south-east, leaving them in a fading westerly breeze. The lead pack of four managed to stay with the wind from the front after the gybe for just long enough to escape the high. They moved into the strong southerly that sets up along the west coast of South Africa as the high pressure came in behind them.


Drag race


The front four found themselves in a straight line drag race to the finish, with MAPFRE finishing on Nov 24 at 15:10UTC with Dongfeng Race Team almost three hours behind at 18:02UTC, then Vestas 11th Hour Racing at 19:37UTC and Team Brunel on 25th November at 00:14UTC. This was a brilliant recovery by Dongfeng who were back in fourth once the fleet had converged, twenty miles behind second placed Team Brunel in Image 6 from 00:30UTC on the 20th November.


I think they achieved this just by good speed and consistent sailing in the big breeze and waves of the cold front. If you look at Image 8 taken just 36 hours later at 12:00UTC on the 21st November, Dongfeng Race Team are already back up into second and leading the chase to MAPFRE. In these conditions at least, it looks like this is a two-boat race around the world.


Image 8 -??Geovoile


Of course, there’s a lot more to the rest of the race course than the Southern Ocean, and we will see plenty more tactical and strategic opportunities – like the convergent wind line that Vestas 11th Hour Racing found in the Med to take the lead in Leg 1 – to keep the pot boiling and the podium turning over.

Restart and a Fastnet


A final word on the back three, who all had to dive all the way south to find new breeze as they were swallowed by the high pressure. Check out Image 9 from 05:00UTC on the 24th November, with all three boats virtually side by side with 605 miles to go to the finish – about the same distance as a Fastnet Race. The gun goes and the restart starts...


Image 9 -??Geovoile


They were all on the leading edge of a new low pressure system that was moving east and pushing the light air and high pressure away, keeping them in solid breeze. Nothing much changed for the next 24 hours, they were still within three miles of each other at 08:15UTC on the 25th November in Image 10, with Cape Town to the north-east. The low was headed south-east, and there was a wall of high pressure between them and the finish.


Image 10 -??Geovoile


Things looked worse than they were, fortunately the high was going east too, and they crept around its eastern edge, eventually ending up dead upwind of Cape Town in a solid 18-20 south-westerly that was slowly shifting to the south – Image 11 from 13:00 on the 25th November.


Image 11 -??Geovoile


Persistent shift


A persistent wind shift like this is a very straight-forward tactical situation that any dinghy sailor would recognize, and everyone knew what to do – sail until you can make Cape Town on starboard, and gybe. It came down to boat speed, and Team AkzoNobel’s experience was starting to pay. They eked out a four to six mile lead over the other two that they maintained quite comfortably to finish fifth later that evening, November 25th at 21:24UTC.


The fight to avoid the wooden spoon went all the way to the wire with Team Sun Hung Kai/Scallywag eventually shading it, finishing at 21:55 and 21seconds UTC with Turn the Tide on Plastic one minute and eight seconds behind.


Old rules rule


Looking back, it was a relatively straight-forward leg. The fleet were straight into the trade winds out of the start, the Doldrums were gentle on them, and although the South Atlantic was a complex mess as they approached it, in the end the old rules ruled.


So I’ll conclude with the old rule for Leg 3, down through the Southern Ocean to Melbourne: keep going south till it’s blowing 40 knots, then turn left and hang on. We’ll see how well that one works out starting 10th December...

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