Team AkzoNobel paid the price for their courage, Turn the Tide on Plastic capitalized on their caution, while out the front Dongfeng Race Team and MAPFRE just looked in a different league...
This big, big week was already set up on Monday, when we published the last Strategic Review. If you’re a regular reader of these Reviews and up to speed on how the situation was expected to unfold, then skip ahead to the section Let’s dig in.
If not, then the quick version is that the fleet was skirting the bottom of a bubble of high pressure and light winds, about to transition into the main climate zone for this leg – the Westerly Storm Track – and grab a ride on their first east-bound low pressure system.
If that sounds like hard work and you’re short on time, then the Cliff Notes version is that the start and finish – Cape Town and Melbourne – of this leg both sit at latitudes normally dominated by stable, semi-static areas of Subtropical High Pressure. To get between these areas of high pressure, the traditional strategy is simple: keep going south till it’s blowing 40 knots, then turn left and hang on.
Dive into the Storm Track
The fastest route for this leg has always been to get south away from the influence of the high pressure and its light winds, and dive south into the Westerly Storm Track, the latitudes where storms and low pressure systems swirl west-to-east around the globe, circulating the Antarctic with nothing but a handful of tiny islands to slow them down.
There’s an art and a science to riding these storms, keeping the boat in the band of strong north-westerly winds to the north-east of the centre of a low. Don’t get too close to the centre, or the boat will get hammered and might break gear. Equally, don’t get too far north where the wind is lighter, as the boat will slow and the low pressure system will move ahead and leave the boat wallowing in its wake.
Ice, ice baby
And the final thing to think about for the strategy for this part of Leg 3 is the Exclusion Zone set to keep the fleet clear of Antarctic ice drifting north. It’s a line stretching from west to east and it is marked on the Race Tracker in red. If a boat goes over that line it will get a penalty, the seriousness of which is judged by the Jury depending on the circumstances of the infraction.
Round the high
We left the fleet at 13:00UTC on 11th December tip-toeing round the southern edge of the high pressure, as we can see in Image 1.
©Geovoile - Image 1 (Click for larger image)
It was a race to the south to get into the stronger breeze from the low pressure system you can see at the bottom of the picture. So far, so good... the problem was the forecast: a new low pressure system forming to the north-west of the fleet, spinning up and quickly moving east to overtake them, bringing 40 – 50 knot winds and some monster waves.
We can see the fastest potential route in Image 2, a Predicted Optimal Route from the fleet position on Monday through to 20:00UTC Wednesday, the evening of the 13th December.
©Geovoile - Image 2 (Click for larger image)
It goes without saying that placing the boat in the path of a serious storm is fast in theory, but it doesn’t allow for the potential for breaking something or someone. A more conservative option would be to position further north, where conditions would be more moderate.
A second problem was the Exclusion Zone – the red line is just about clear in Image 2 to the south of the fleet. At this point they were predicted to be reaching with 30-40 knots on their beam and converging with the Exclusion Zone. There was a chance that to stay clear of the Zone they might have to harden up and narrow their wind angle – both dangerous and slow in that much breeze and big waves.
Again, it would be safer and more conservative to stay further north, with a bit more room on the Zone... but the route would be slower than that taken by anyone who went south, kept boat and crew in one piece, and didn’t get pinned against the Zone.
Let’s dig in
All right, so much for the background, let’s dig in and see how it played out. In Image 3 we can see that by 05:00UTC on Wednesday morning, 13th December the fleet had picked their lanes to set up for the storm, which is now clearly visible forming to their west.
©Geovoile - Image 3 (Click for larger image)
Turn the Tide on Plastic (light purple) took the northern option, gybing at about 22:00UTC on the 12th December. They were followed less than an hour later by Vestas 11th Hour Racing (orange), but the latter only did an hour on port gybe before returning to starboard. Team Sun Hung Kai / Scallywag (grey) was initially with these two boats, but didn’t gybe. It left them sailing a lane just to the north and parallel to the leading pack of Dongfeng Race Team (red), MAPFRE (white), Team AkzoNobel (dark purple) and Team Brunel (yellow) – all four of whom remained committed to the south.
The storm strikes
The whole fleet had relatively similar conditions at this point, a light to moderate south-west to westerly wind. That changed quickly as the storm approached and their choices began to play out. The wind went around to the north, and began to build.
We can see in Image 4 from 12:30UTC on the 13th December that positioned to the north, Turn the Tide had a north-westerly wind eight to ten knots lighter than the north-easterly seen by the boats to the south. The boats in the south were sailing narrower wind angles at this point – 70-80 degrees – because they didn’t want to slip further south, closer to the Exclusion Zone.
©Geovoile - Image 4 (Click for larger image)
It was this moment when Vestas 11th Hour Racing saw an opportunity, they put the bow down, sailed a wider wind angle with a bigger sail and a lot more speed to come hammering out of the north, cashing in their leverage.
In Image 5 from 15:00UTC on the 13th December we can see them converging with the fleet and grabbing third place. Check out their wind angle (127 degrees compared to 80-100 for the rest of the lead pack), and their speed, almost four knots faster. Given that they were sixth two days earlier, this would have to be regarded as a result for their northern strategy.
©Geovoile - Image 5 (Click for larger image)
Why did they pick this moment to give up their northern position before the very worst of the storm hit the fleet? We can see the reason in Image 6 from 21:00UTC on the evening of the 13th December. The cold front associated with this low pressure is right on top of the fleet, shifting the wind from a northerly in front of it, to a more westerly wind direction behind it.
If you look carefully at the table of data in Image 6 you can see it happening.
©Geovoile - Image 6 (Click for larger image)
The leading, most easterly boats, Dongfeng and MAPFRE still have a northerly wind direction (355-360), while those behind them all have more of a north-westerly (330).
This wind shift is happening much earlier than was originally predicted in the forecasts we looked at on Monday (compare Image 6 to Image 2). And it’s important because once the wind was blowing from the west the risk of getting pinned against, or fouling by entering the Exclusion Zone was vastly reduced. The westerly wind was blowing from behind them, making it possible to gybe away from the Zone.
Trading leverage for speed
So Vestas 11th Hour Racing felt that they no longer needed the same safety factor, the extra distance north above the Zone. They traded their leverage for speed, and rejoined the pack to take the gain while they could – nice sailing.
The passage of the front significantly opened up the strategic and tactical options as we can see in Image 7 from 08:00UTC on the 14th December.
©Geovoile - Image 7 (Click for larger image)
The leading pack all gybed a couple of times to stay south, and close to the Exclusion Zone. The advantage of the south was that the wind had more of a northerly component – it was 330 rather than 270. Compare Dongfeng’s wind direction in the table in Image 7 (325) to Team Sun Hung Kai/Scallywag (270).
A boat sailing in a 330-wind could sail straight at the finish line at a very fast wind angle. While those in the 270-wind direction were forced to gybe downwind, sailing what’s called VMG (Velocity Made Good) angles, away from the direct course and losing significantly to those in the 330-wind direction.
Having a moment
Dongfeng Race Team and MAPFRE did a beautiful job throughout the preparation for and onset of the storm, positioning perfectly for maximum gain. They took the risk of committing to the south, but delivered on that commitment and ambition with safe, fast sailing – although even they have had their moments.
Paying the price
Back in the pack, Team Brunel now took a more conservative option in the westerly wind, holding onto port gybe to reposition further north before they gybed. They lost out to Dongfeng and MAPFRE, but not to Team AkzoNobel. The Dutch were pushing as hard as anyone to say south, but they paid the price of their ambition with a bad gybe.
Meanwhile, Turn the Tide on Plastic now moved south back towards the pack, passing Team Sun Hung Kai / Scallyway, who – after a taste of the Southern Ocean – were also changing to a more conservative strategy, taking the most northerly position in the fleet. Everyone rolled east with the system for the next 30 hours and as conditions eased, strategies and routes converged. Everyone – except the damaged Team AkzoNobel – has headed for the Exclusion Zone, and started to gybe along it. This takes us to the current situation in Image 8 at 13:00UTC on the 15th December.
©Geovoile - Image 8 (Click for larger image)
We can see that the south is still the better place to be for the leaders, with more wind at a better angle for going east towards Melbourne. Everyone will need to stay south to avoid the region of light wind that’s visible in the top right of Image 8. The situation won’t change for a while, the south should remain the place to be...
In Image 9 we can see the predicted situation for 11:00UTC on Monday, the 18th December.
©Geovoile - Image 9 (Click for larger image)
It shows the fleet’s Predicted Optimum Route through the next three days as the big storm fades behind them, and the bubble of light air turns into a high pressure system to their north. There are no strategic options here, everyone will have to stay south, right on the edge of the Exclusion Zone.
If we look even further ahead to 07:00UTC on the 22nd December (next Friday) in Image 10 it’s more of the same, with the fleet gybing to ride the storm track and stay locked onto the Exclusion Zone... until the moment when they have to turn north for Melbourne.
©Geovoile - Image 10 (Click for larger image)
It’ll be a drag race – albeit a very quick and drama-filled one – until this moment, when they prepare to jump off the conveyor belt of the Westerly Storm Track for the final approach to the finish. I’ll be back to review their options before they have to make this next big decision.
EDITOR'S NOTE: Subsequent to Mark submitting this story, the Antarctica Ice Exclusion Zone was pushed further to the north. The effect has been to close off the options for the southern boats, who will now just sail along the Exclusion Zone limit on a northeast heading. It will likely result in a convergence of the fleet at the northwest corner of the updated limit, to the north of the Kerguelen Islands.