Fastnet Navigators testing new Tidal Stream technology

by Media Services on 4 Aug 2009 The Fastnet race has often been described as a 'Navigator’s race' due to the complexity of options presented by the changing weather and strong tidal streams down the English Channel coast.

This year’ s race will be no exception with every headland offering the prospect of major gains (or losses) as navigators scratch their heads about whether to duck in out of the tide or to head offshore.

One of the biggest headaches for navigators is the mass of pre-race preparation including the filling in of endless pages of tidal atlases.

This year’s race will leave all that in the past as Fastnet navigators sign up in droves to test new electronic tidal stream data which promises to consign paper and pencil to the chart table drawer forever .

Late last year, former RYA Chief Instructor Penny Haire teamed up with Team GBR’s Olympic tidal consultant Dr Roger Proctor to form Tidetech- a company dedicated to making high tech tidal prediction technology available to sailors.

Tidetech’s new service produces data using a numerical model which can predict tidal streams with an accuracy of up to 95%, every 15mins for every 0.5 mile in the English Channel and 6 miles for the rest of NW Europe.

The data is in electronic format and automatically takes account of the time, date and phase (i.e. Springs, Neaps or in-between)- thus no maths required!

The data is sourced from the UK’s Natural Environment Research Council’s Proudman Oceanographic Laboratory (POL) - a world leading centre in tidal and storm surge prediction.

The model has become the UK’s official ‘operational forecasting’ source of tidal stream data and informs major decisions such as whether to raise or lower the Thames Barrier.

Now Tidetech are making it possible for everyone to use this incredible technology- by producing it in a format (GRIB) that can be read on most PC electronic chart plotters.

This means that navigators can instantly see the tidal strength and direction at any point on a chart and go forwards and backwards in time.

The availability of this GRIB format data has meant that race routing can be much more precision as has been proven in recent days in Australia's Sydney to Southport race.


In that race armed with tidetech's GRIB formatted data, the winners went much wider than ever before, able to avoid the strong south flowing East Australian Current.

The real benefit is to be found in passage planning. Some chart plotters perform optimal routeing functions that work out the fastest route from A to B using a wind GRIB and polars (yacht performance data).

This gave useful results, but navigators still have to work out their course to allow for tide using traditional paper methods. Now, at last, navigators will be able to use wind and tide GRIBS together to give them the fastest route simply, quickly and with far greater accuracy than ever before.

A custom service is available for the Fastnet Race. Visit http://www.tidetech.org/rolex-fastnet-race-2009

A range of other Tidetech GRIB files are also available for a free trial before a subscription service is launched in the coming weeks. For more information see www.tidetech.org