For the past couple of days, the fortunes of the six competitors in the Volvo Ocean Race have been waxing and waning - if you believe the official results which show regular lead changes, and some quite dramatic moves - occurring even over just the space of a couple of hours.
Using the Predictwind.com?nid=94219
routing system, we get quite a different picture from the 'who's closest to Auckland approach' adopted by the Volvo OR reporting and tracking system.
The reality is that the boat which does sail the shortest distance is probably not going to win, and would most likely finish well to the rear of the field.
Taking a time to finish approach we see a much steadier picture - and usually the boat that completes the course in the shortest possible time wins, doesn't it?
The reality is that the fleet have to make a trade-off between sailing the shortest possible distance to Auckland, and getting into part of the ocean that will have the strongest, most consistent, and most favourable direction - even if they have to sail additional distance.
The downside of the latter tactic is that the wind could well fill in, so those who have opted for the more direct course get the benefit of fresher than expected breezes, and effectively cut the corner on the boats that sailed to the east - which is where the fresher breezes are currently residing. First to the corner
Readers of the crew blogs will be well aware of the fact that the boats have been heading upwind in moderate to fresh head winds and thumping into some big seas. As the wind has softened, the boats that are on the more easterly side of the direct line to Auckland have been getting better speeds in fresher breeze, albeit at the expense of sailing some additional distance.
But the fact of the matter is that Camper was first past an effective waypoint this morning, the southern end of Taiwan, with Groupama in second.
Those two have been leading the fleet, with Camper in front, and opened up a gap of 20 miles or more on the trailing boats.
Telefonica have been making some interesting decisions - they were lined up to hit the southern peninsular of Taiwan (a deliberate move, presumably to get some shelter from the big swells and sail at a faster speed). The trade off from that move is that she had to swing right and sail down the Taiwanese coast, giving away valuable time for her softer, faster ride.
Then she continued south, but struck light winds and headed east following Camper, and also Groupama.
Telefonica’s options - take the blue course and stronger winds, but pick up more distance. The wind speeds can be read off the coloured legend at the bottom of the shot - PredictWind.com?nid=94219
There is no definitive way of saying at this point who will win the leg. Certainly it is possible to run weather routing software, like PredictWind.com which will produce any number of options and permutations. However in a leg like this, with about 17 days to go - it is not accurate, as we only have weather for nine days ahead.
PredictWind will continue to produce a route longer than nine days, but it extrapolates the weather at the end of the nine day period to stretch a further eight days, in this case. A compromise approach, but as far as we know, only Ken Ring?nid=94219
claims to be able to forecast for a longer period - a year ahead in his case! A new deal
Today, Sail-World took a different approach - which is to run the full route, drop a mark back up that track nine days sailing from the current position for each boat, and then look at the options and distances. The process was repeated for the most easterly and westerly boats, so that the mark was fairly positioned for both extremes.
With this approach the situation became clearer.
Instead of a widely fluctuating lead, we had a closer more consistent pattern that would be expected of a closely fought yacht race.
Camper’s options are more aligned - meaning that the certainty of the route prognosis is high. The wind speeds can be read off the coloured legend at the bottom of the shot - PredictWind.com?nid=94219
For the past day or two the breeze in the Phillipine Sea has been predicted to crumple from the west and be stronger in the east. Given that a knot of wind speed usually equates to a knot of boatspeed in a VOR 70, a stronger breeze - even if only a couple of knots or more becomes very significant over a 23 hour or 48 hour period..
The long story short, is that while the boats heading out to the east, are getting into stronger breeze, they are not really sailing closer to Auckland. But they are setting themselves up for a fast ride once they hit the trade winds and can sail a faster more direct course.
Those who opt to head for Auckland early might save themselves a bit of distance, but they do have some light winds to negotiate - in some cases under five knots. Where if they had opted for a more easterly route, they would be in 19kts winds - that's a difference of about 15nm an hour in terms of distance - and would see a big lead built- and rapidly.
weather routing is based on two independent basic feeds, which a routing program refines and modifies these basic feeds for a variety of factors, including ocean currents, terrain and accuarcy of the feed, and then produces an optimum route.
The strength of the system is in the independence of the feeds. Simply if the two feeds produce a similar route, then a navigator can have a high degree of confidence in the accuracy of the route. But if the two routes are quite distanced from each other, then the degree of accuracy is low, and it is up to the navigators to make a call. Typically they will play for time until the two routes do start becoming more aligned, or play with the options and try to understand why the two routes are showing a significant variation, and make their move accordingly. Go north. Go inside !
Race positions after exiting Taiwan. Camper is the most east, under the green pin. Telefonica’s earlier big course alteration can be clearly seen. - PredictWind.com?nid=94219
Some of the computer generated routes we have seen over the past few days have been markedly different, including some for a time that recommended passing between Taiwan and the Chinese mainland on the way east.
The beauty of the computer based system is that it is possible to move the boat to a different location and see what difference that option makes, and then come to an understanding of what is required and the expected outcomes.
What we are seeing with today's routing, is that those boats in the east are showing a much higher degree of certainty in their course options from Predictwind, while those to the west, still a good option to the east, but if they elect to turn right (south) and take the more direct route (and we are talking about 400nm difference over just 2700 total distance sailed) they will still have to negotiate a minefield of significant soft periods of wind in the next 24-48 hours.
In summary, we are pretty confident that Camper is leading and will hold her lead, followed by Groupama.
Behind those two it is anyone's game, but again those who get further east before turning south, will get the best ride, provide they don't clock up too much extra distance.
We'll be rolling the virtual mark closer to Auckland each day, and see how the race unfolds – and keeping you updated.
The key question will be whether Camper can consolidate the gain she should get from her move to the east and then get across the front of the other competitors, and play the old covering trick of staying between them and the finish line.
From what we have seen, she does not appear to have any speed issues on this leg. Groupama looks very good, too. The other question will be whether Telefonica can pull it back over the next couple of days? A win to Camper and a fifth place finish for Telefonica would wipe out almost all her points lead in one blow.
Meanwhile in the last six reports, we have four leaders - when by another method the same boat has been in front all day.
Navigator Will Oxley delves into some chocolate onboard CAMPER with Emirates Team New Zealand during leg 4 of the Volvo Ocean Race 2011-12, from Sanya, China to Auckland, New Zealand. - Hamish Hooper/Camper ETNZ/Volvo Ocean Race© Click Here to view large photo