Wellington to Rio - the toughest leg VOR 2005-2006

by OR Media on 19 Feb 2006 At 6,700 nautical miles, leg four is easily the longest leg in the race, with lots of challenging conditions along the way. Weather-wise, it is a leg of two halves - Wellington to Cape Horn and Cape Horn to Rio – testing the sailors and the boats alike in just about every imaginable weather and sea condition.

Logically the leg can be further divided into five sections: the start, the Southern Ocean, Cape Horn, the South Atlantic, and the finish in Rio.

Looking ahead, it will not be long before the crews need to plan for the first front expected to pass over their course. The fleet should see winds build from the north as they sail away from Wellington. The clouds will continue to build on Monday as a polar low passes south of New Zealand. A cold front extending northwest out of the low will pass early Tuesday, bringing showers and a shift from northerly to south westerly winds.

Once again, the Race Committee has added a set of ice gates into the course definition in order to keep the crews from sailing too far south and into possible danger.

This will force the fleet well north of the great circle route, making for a safer but more tactically challenging course to Cape Horn. In addition, the experience gained on Leg 2 has taught the teams that strong winds are not the only ingredient to a winning strategy.

In fact, with the Volvo Open 70 class, they will be keen to stay in winds less than 30 knots if at all possible. Once the winds get too strong, they actually need to decelerate in order to stay under control. They can get to boat speeds of 25 knots in winds under 30 knots, winds over that either risk damage to the boats or the crew members.

Thus the tactics will be focused on the timing and locations of the passing polar fronts and staying in the optimum wind speed and wind angle.

Other than the changing weather conditions, nothing but icebergs and water stand between the boats and Cape Horn.

Ice will be a constant concern through this leg. As temperatures warm up through the southern hemisphere summer (December-February) the winter ice which forms around Antarctica breaks free to form icebergs. While the sea ice max is in October, the iceberg max is late summer, just as the boats are making their way towards Cape Horn.

In addition, as they sail east, the Antarctic Peninsula extends north, forcing the boats closer to Antarctica and increasing the risk of ice.

The Volvo Ocean Race managers have been working hard to minimize the risk of ice for both Southern Ocean legs of this race. The Race Office has been working closely with C-Core, a Canadian remote sensing firm, to analyze radar scans of the southern Pacific Ocean in the hopes of identifying areas with possible icebergs.

C-Core has provided the race office with dozens of radar surveys which they hope will keep the Volvo fleet from the worst of the ice and prevent any of the ice encounters which were common during the last race. It is this analysis that led to the placement of the ice gates in this leg.

Cape Horn, at the exit of the Southern Ocean, is the subject of much maritime lore. From a meteorological and oceanographic perspective the reality can be a flashpoint of converging forces. With the mountains of South America extending south and the Antarctic Peninsula extending north, all the weather of the Southern Ocean is forced to accelerate through the narrow gap.

Much like you can increase the water pressure coming out of your garden hose by covering half with your thumb, the winds too often increase as they pass Cape Horn. In addition, the water depths south of Cape Horn suddenly decrease from several kilometres to only a few hundred meters, making for huge often breaking waves.

For a calmer trip around Cape Horn the boats would have to stay south as they round the Horn, but one hardly signs up for the Volvo Ocean Race in search of a calm trip.

Rather, each team’s strategy for rounding the Horn will depend on maximizing speed and setting up a good position for the trip north along the South American Coast.

Much like passing Eclipse Island was far from the end of leg two; passing Cape Horn is only the beginning of the second part of Leg 4.

While the first half of this leg often gets all the hype, it is not always the case that the first part is the most dangerous. There are many examples of past races where boats have been damaged in the big wave, light wind sailing on the east coast of South America.

In addition, after the wilds of the Southern Ocean, sailing close to land will add challenges to the already difficult job of the navigators. The timing of the tidal gates and fluky winds off the land could make the Straits of La Marie a windfall for some or a frustration for others.

Strategy for the trip north from Cape Horn to Rio depends on the position of the South Atlantic high and the current off the east coast of South America.

With a strong high pushed east, teams may find it valuable to sail the extra distance and go outside the Falkland Islands.

On the other hand, a weaker high, or one that is further west, would see the boats staying close to the South American coast. Either way there is a good chance the boats may be sailing upwind in light northerly winds as they try and use the Malvinas (Falkland) current to their advantage.

There are even more icebergs just northeast of the Falkland islands for which the fleet will need to watch out.

Further north the question of staying inshore or offshore will be complicated by thermal sea breezes off the shore and by the Brazilian current which will flow south against the fleet.

Likely conditions as the fleet closes on Rio will be as testing as the rest of the run from the north of the Falklands, complicated by the variables thrown up by the proximity of land and the high ground around the goal.

Rio has a reputation for light winds close in and the boat that gets cleanly to the finish line will be relieved indeed.

During the 6,700 nautical miles of this leg, the teams will face just about every kind of weather possible.

Snow, sleet, fog, ice, rain, hail, even a chance of sun; then gales and calms will make for good competition and an exciting leg.