KEY PRODUCTS - ROUTEING SOFTWARE
Expedition
This PC-based race and routeing software was developed by former Volvo
Ocean Race navigator Nick White and has been much expanded over
the years. In the English-speaking world it’s a favourite at the top end of
the sport, both for inshore racing, where starting and layline functions
come to the fore, and o shore, where routeing is of most value.
Additional functionality includes a facility to display the YB
Tracking positions of other vessels, plus a table that shows gains/
losses compared to other boats since the previous report. With
the addition of electronic charts, Expedition can also be used for
chart-plotting (illustrated above) and will display AIS targets.
The downside is it’s a relatively complicated system that’s not always
intuitive. Some time is therefore needed to learn how to use the software.
Price: £950
expeditionmarine.comAdrena
Another PC-based system, this is a favourite among French-
speaking sailors, from Figaro sailors and Vendée Globe skippers to
amateurs competing in events such as the TransQuadra. Again it’s a
sophisticated system that takes time to learn, but has a more intuitive
interface than Expedition, and English language is included.
Price: €1,083 ex VAT (approx £970)
adrena-software.comBUYER’S GUIDE WEATHER ROUTEING APPS
I
t’s not long ago that weather routeing
could only be run on PC-based
applications such as Expedition and
Adrena. While these are still popular at
the high end of the racing scene, there are
now many more options that bring the key
bene ts of routeing to a wider audience.
ere’s an increasing trend towards
routeing being calculated on remote
servers, rather than on so ware carried on
board. e results can then be displayed
on a smartphone, tablet, PC, or even an
MFD/chartplotter. In the latter case a
number of manufacturers are working
with companies such as PredictWind
to provide this functionality.
However, as the Racing Rules of Sailing
stand at the moment, when racing the
calculations must be carried out by the
so ware on board the boat and not on a
remote server. Otherwise it’s seen as outside
assistance on the basis that an external
source has provided tailored information
for your boat, even if no human input is
involved. ese services can therefore
only be used before the start of a race.
Routeing so ware is no substitute
for the understanding of weather
systems, including features such as
troughs and fronts, and the formation
of low pressure systems. And it’s still
important to analyse the e ects these
will have on your potential route.GRIB FILES
ese small data les contain the
weather information needed for routeing
algorithms and to enable the data to
be visualised on screen. However, it’s
important to be aware of a number
of drawbacks to GRIB data. A key
disadvantage is that they don’t display
weather fronts. Even worse, many GRIB
viewers interpolate on an hourly basis,
even if data is only available in three-hour
or six-hour steps. e e ect of this is to
further mask weather features. It’s therefore
also worth downloading synoptic charts- black and white les are small enough
to download over a satellite connection.
It’s also worth noting that GRIBs tend to
underestimate higher wind speeds and may
not be reliable in less than 8 knots of breeze.
e latter point can have a large bearing on
routeing outcomes, particularly on boats
equipped with a Code Zero, where high
speeds can be achieved when reaching, but
upwind and downwind VMG is very low.
WEATHER MODELS
e most commonly used weather model
for routeing is the global American GFS
system, simply because it’s available freely.
However, there are other options that o er74 Yachts & Yachting August 2019 yachtsandyachting.co.uk
Below
Like most
other systems,
SailGrib will take
GRIB fi les from
multiple sources