Geronimo's route north should help avoid icebergs and the worst of the Southern Ocean weather

Geronimo has spent the last 36 hours of her Jules Verne record attempt heading north from 50 degrees south to 45 degrees. While this is not the most direct route, it has helped minimise the impact of the continuous depressions which develop along a polar front, where warm moist air clashes with the cold dry air from the south. Olivier de Kersauson reported from the boat this morning: “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 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.”

As well as dodging the worst of the weather, the crew are now constantly monitoring the sea water temperature which gives an indication on the likelihood of ice. They are also closely monitoring the radar (every 10 minutes or 12 nautical miles) watching out for ice bergs which appear as spots! Since passing the Kerguelen Islands, the temperature has fluctuated between 3°C and 7°C. De Kersauson added:”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.”