 Fog,
ice, current and a never-ending string of lows make the Transat a
tactical minefield. Elaine Bunting spoke to weather router Ian Moore
about the hurdles the solo skippers will face"From the start,
the course will keep the fleet fairly close the south coast of England
because they have to leave a waypoint off the Lizard to port. Then
they're free until Boston. There is a possibility that they will put
in a waypoint to be left to starboard to stop the boats getting into
the ice region, but the boats are basically given a huge amount of
scope.
"Getting a good departure and the first shift out of the UK is
critical. At the west coast of Ireland you can get a small low stagnating
and if you want to get round that corner you either have to go very
close inshore or stay offshore; that could be one of the first stumbling
blocks.
"From there to the middle of the Atlantic should be relatively
simple. There will be a series of lows coming off North America or,
more likely, Canada and tracking across the Atlantic. The north-south
position of the North Atlantic High will dictate how far north the
lows are tracking, so it will dictate everything.
"The further north you go, the less distance you've got to sail.
At the same time you would have to go along way north in the summer
to go downwind - and there is rarely any way through to the south
if there are westerly conditions. But to actually go on the north
side of those lows is a very big ask.
"So the race is predominantly beating. They'll probably try to
get just south of the track of the lows and use the shifts a great
deal. They'll use the southerly and northerly shifts on each side
of the low to get some reaching angles. When it's south-westerly,
they'll be reaching hard on port and when it goes to the north-west
they'll reach hard on starboard to get back to the next south-westerly,
so passing just below the centre of the lows.
"The monohulls will be trying to find as much breeze as they
can find at a true wind angle of 60-70°, when they'll still go
faster the more breeze they have, until they run into problems with
sea conditions. The multihulls, however, are much more affected by
sea state conditions. A monohull goes faster in 30kts than it does
in 25kts, whereas multihulls don't. They'll still have to be far enough
upwind to get the northerlies and southerlies, but they'll want to
avoid extreme conditions because of sea state and because they don't
go any faster. However, they're traversing systems quicker, so it
does give them the option to use weather systems more tactically.
"Current could be massive. You've got to try and avoid the Gulf
Stream on the way across and when you're two-thirds of the way across
you're thinking if you can use any of the eddies. It can be absolutely
huge if you get it right; you can make 20-30 miles on an eddy.
"They are about 50-60 miles across and at any given time there
are probably about 4 or 5 main eddies on either side of the Gulf Stream.
They move around and while they're not as predictable as the core
of the Gulf Stream, they can make a huge difference, particularly
if it's not a particularly fast race. It's not unusual to find 2kts
of current in an eddy, or even more.
"The information you can get depends on the weather conditions.
You're looking at sea surface temperature plots from the US and if
there's not too much cloud cover they are very accurate. There are
a number of models, effectively GRIB files, which are based on that
SST imagery and there are other indicators, such as floating buoys,
which add data to the equation.
"When you broach that line on the north side of the Gulf Stream,
the temperature drops dramatically, from 22 or 23°C to 10-12°C.
That's where the main effects of fog are felt. It's a nightmare for
solo sailors, but it's not part of the strategy - it's just one of
the hazards you've got to put up with.
"There can be as little as 50 miles between the Gulf Stream and
the ice. Then you've got to thread the needle. If [the organisers]
put in an ice waypoint, everybody will tend to congregate there, relatively
far north, and try to use some shifts. As they come round that corner
they'll be held at that latitude. At that stage, they're only 800
miles off the coast of America and that's the point where they'll
have to decide how to get down to Boston.
"At about 44°N, 50°W, you start to pick up the Labrador
Current, which is very, very cold. Although it's not as strong as
the Gulf Stream - maybe just a knot, - you still have to use that
to your advantage to get south.
"It's very difficult to say what the weather conditions are going
to be; it can be variable. Because the water's cold it tends to make
things very stable - you don't get the mixing and cumulus and stuff
you get over Gulf Stream water. So while it can be windy in the Gulf
Stream, it can be quite light over the cold water.
"It will get very tactical there, and there's a chance you could
have to beat all the way down that coast. In my experience there would
only be a 10-15% chance of spinnaker conditions over the entire race."
Ian Moore, 33, is a professional navigator and weather router. He
was navigator on Illbruck during the last Volvo Ocean Race, has been
weather router for Emma Richards and Mike Golding, but his main job
is navigating maxis such as the new Morning Glory and Sagamore.
Photo: DPPI |
