Volvo Ocean Race- Dongfeng loses lead, anyone's race ahead of Doldrums
by Richard Gladwell Sail-World.com/nz on 20 Oct 2014
Smiles aboard Mapfre - Anthony Marchand and Michel Desjoyeaux, very good friends and very good sailors. Volvo Ocean Race - Team Campos - Francisco Vignale
http://www.volvooceanrace.com/
The Chinese entry Donfeng Race Team, has lost her lead on Day 9 of the Volvo Ocean Race, with boats on the east and western side of the course threatening.
Two hours before the most recent sked at 0640hrs UTC, Dongfeng was still being listed by Volvo Ocean Race as the leader.
But when the 0640hrs Sked was released VOR showed the Dutch entry, Tema Brunel to be the new race leader in terms of distance to be sailed to Cape Town.
Using the routing function of
Predictwind Team Brunel is calculated to be in fifth place - at the next turning point of Fernando de Noronha, and archipelago 220nm off the Brazilian coast.
The Predictwind calculation are based on 'sailing' the boat through expected winds en route to Fernando, using a polar for a VO65 yacht, of the one-design type sailed in the race.
The output from Predictwind shows the the expected arrival time at a waypoint, or finish, and also calculated the distance to be sailed to reach that point as quickly as possible. It follows that a boat can sail faster, due to increased breeze, cover more miles, and arrive ahead of a boat sailing at a slower speed but a shorter distance.
The Volvo Ocean Race leaderboard only calculates on the basis of distance to be sailed on the Great Circle Route (the shortest distance between two points on a sphere), and ignores the effect of weather along that route.
Using weather routing to predict finish times, the Spanish entry Mapfre is the race leader, followed by the Danish entry Team Vestas Wind, with Donfeng, third.
Nine hours earlier, the routing showed the two most western boats Team Brunel and Abu Dhabi Ocean Racing, were the best placed, and looked to have a good run through the Doldrums. Usually the maxim of 'west is best' applies on the race strategy for this leg of the race, but in this 2014-15 event the east seems to be paying an unusual dividend.
The route for Abu Dhabi, looked to be agreed using both weather feeds for Predictwind, and Dongfeng, as then race leader tried to get across the track the two western boats.
But now the situation has changed dramatically with the two eastern-most now looking to have a good course from the routing software - however it does represent a significant deviation away from the most direct route, and in terms of navigational strategy, following extreme courses usually carries a very high risk.
Despite the variance in places based on times to Fernando the time different between leader Mapfre and fifth placed Team Brunel is only just over an hour.
On that basis the race is very close, judging the correct entry point to traverse the Doldrums is critical. Once the boats emerge, the remainder of the leg is expected to be sailed in steadier, stronger winds, with little opportunity to make radical gains.
The narrative at 0430 UTC by Volvo Ocean Race is as follows:
Leader: Dongfeng Race Team
Spread of fleet: 85 nautical miles
Wind speed: 13-11 knots
Sea state: moderate
Boat speed: 15-12 knots
The fleet has been split by the Cape Verde Islands with three going south and four north.
Leaders Dongfeng Race Team opted for the southern route, in the gap between the Windward and Leeward Islands. The Chinese boat was chased by MAPFRE and Team Vestas Wind with the Spanish crew just ahead of their Danish rivals.
The four-boat northern charge was led by Abu Dhabi Ocean Race, pushed by Team Brunel, with Team Alvimedica and Team SCA trying to close the gap behind them.
The boats going through the Windward/Leeward gap would benefit from a funneling effect as the wind compressed and accelerated between the islands.
However, the payback came from the wind shadow left by such tall lumps of rocky outpost. Team Alvimedica navigator Will Oxley estimated the effect to last as much as 100 nautical miles beyond the obstruction.
The fleet now are meshing back together, Dongfeng from the east and Abu Dhabi Ocean Racing from the north.
The early advantage that the Chinese took is being eaten away by the western group which has five knots more wind and a better angle. Abu Dhabi Ocean Racing has a speed over the ground of 15 knots while Dongfeng is recording only 12 knots.
So in a few hours, and if the situation doesn’t change, Abu Dhabi Ocean Racing should regain the lead.
Next obstacle to overcome: The Doldrums.
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