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2008/02/07 - 18h06
Marine composition
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| Jules Verne Trophy |
| The Indian Ocean is living up to its reputation: unpredictable! Evidence of this comes in the form of a zone of high pressure,
slipping along under Africa and a very big low kicking up a nasty swell past the North of 40°... As a result Groupama 3 is
having to pick its way through beam seas, which are making the sailing uncomfortable as well as tiring out both the men and
the boat.
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The paradox of sailing: whilst Groupama 3 has been racking up a fine day's upwind sailing with 620 miles at an
average of 26 knots, the giant trimaran is continuing to lose its lead over the reference time set by Orange II! And
the haemorrhage is severe: half the 600 miles accumulated two days ago, have been reduced to just 290 miles this Thursday
afternoon... Yesterday's `light patch' experienced by the crew, who were anticipating this loss of ground, is nevertheless
past and during the viseo-conference this Thursday, Franck Cammas appeared more serene, explaining that the 'scar' was going
to close up again in half a day...
"The weather's not very fine and there are shifty winds and messy seas.
We have seven metre waves, but they're short and it's difficult to know what sail to hoist as the breeze is changing very
quickly, passing from 20 to 28 knots: we'll have to limit the impact as much as we can! In this way the boat goes very fast
at times, making over thirty knots, and then comes to a stop sharply: it's not easy to control it... We still have twelve
difficult hours ahead of us, then the swell will lengthen before reducing. We are in the process of making easting and the
biggest seas should pass in front of us. By Friday, things will be better!"
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A mass of swells... During round the world voyages under sail, in a race or on a record attempt, in solo or crewed configuration, in a monohull
or a multihull, the method of sailing has deeply changed. First off, the boats go faster, then because the sailors are more
experienced and finally because the weather forecasts are considerably more reliable and safe over longer periods... Gérard
Petipas, navigator to Eric Tabarly, recalled during the radio session that: "a compass, a knife and a barometer, that's
what we had to predict the weather..." It was the same scenario for Eric Loizeau, skipper of Gauloises II during
the crewed round the world race in 1977-78, who only had isobaric charts received via fax... Times have changed with digital
files today, which enable not just the forecasting of the strength and direction of the wind over the next five or even seven
days, but also the sea state.
"Multihulls brake in the first instance due to the sea state: we can easily
reach thirty knots but as soon as you have waves, you have to reduce the sail area to limit the speed and the result is that
you end up with more apparent wind. It's this wind, which is dangerous when it varies rapidly, generating impact with the
sea and making the boat go from 25 to15 knots in a few seconds... This is all the more impressive on a trimaran, because with
its three hulls, there is still one wave, which hits the windward float very hard! And the vibrations of this resound throughout
the platform. The blows are pretty impressive..." stated the skipper of Groupama 3.
Now, when a
front generating a strong NW'ly breeze is succeeded by a W'ly wind and then a S'ly storm, these three trains of waves form
an extremely violent pyramid-shaped chaos, which is above all highly unpredictable. This mass of swells, which have mixed
together, create a fearsome undulating disharmony for the structures of multihulls, not to mention the sailors who bathe in
the spray they kick up, smashing against the bulkheads down below and vibrating from head to toe! There can be nothing worse
than a trimaran seasoned by shaker sauce... Fortunately, multihulls have the ability to accelerate to free themselves of the
biggest seas in order to find some more high performance sailing conditions... However, for Franck Cammas and his nine crew,
they'll have to wait until the start of the weekend for that!
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