The Cap Gemini and Schneider Electric trimaran has been heading further North since yesterday, travelling from 50° south to 45° south over the last 36 hours in an attempt to minimise the impact of an enormous weather front.
Geronimo covered 422 nautical miles on Day 24 of her Jules Verne Trophy attempt.
Olivier has given us his latest views on how he is progressing in relation to the record set by Bruno Peyron and his crew. "We're very happy to know that we're in the right sort of timeframe without having had to risk wrecking the boat in the process. I've always said that the boat has to be in good shape when we round Cape Horn, because where we'll really be able to make up time is on our track back up the Atlantic. In the south, anyone can go pretty quickly and keep within one or two knots of the record. A successful round the world attempt relies on fast passages north and south through the Atlantic".
Since passing the Kerguelen Islands, the seawater temperature has fluctuated between 3°C and 7°C, whilst the inside of the boat has remained a fairly constant 6°C. Under these conditions, the crew is constantly monitoring the seawater temperature, because the lower it falls, the higher the risk of ice. "We have a permanently submerged thermometer so that we know the water temperature as well as the air temperature. The first reason for this is that temperature has a major effect on wind direction and behaviour, and the second is that there's a high risk of running into icebergs in these latitudes. In reality though, there's no real rule to go by.
I've seen ice as far north as 42°S in temperatures of 7°C. When you begin to read water temperatures of 0°C, 2°C or -2°C, it's time to take great care: the few bits of ice we're encountering haven't been able to melt and that's the problem. Ideally, we would stay in waters of around 7°C all the time, but that's not always possible. The Antarctic convergence, as it's called, won't let us do that".
On board Geronimo, the Cap Gemini and Schneider Electric crew have a variety of ways in which to detect ice. "A quick glance at the radar every 10 minutes, which is about every 12 nautical miles. At this distance, an iceberg the size of an office block shows up as a spot. Naturally, there are times when visibility is down to zero, but we have an excellent radar system. In this part of the world, the water gets very cold and there's no turbulence to break it up. When it gets down to 4°C, you have to start paying close attention. The guys at the T.A.A.F. polar station tell me that summer was very late arriving this year, which is why there is relatively little drifting ice. They also said that the air in this part of the world didn't heat up as much as usual last year".
In these waters, the crew wear special Fujinon night vision goggles whenever they're on night watch. Human concentration is still the last line of defence against an unwanted meeting with an iceberg. Returning northwards from 50°S lengthens Geronimo's route, but reduces her risk of collision, at the same time as giving her an advantageous position in relation to the low pressure area.