Complex tidal influences for Cowes Week shown in new data from Tidetech

A recently-developed, high-resolution tidal model for the Solent and UK south coast has revealed the complexity of tidal streams and currents in this competitive racing area.

The model details an area including Southampton Water, the entire Solent, the southern sectors of the Isle of Wight and the entrance to Chichester Harbour.

Tidal data of this resolution has previously been the domain of government agencies, oil companies and specialist environmental modelling agencies with access to super computers. Now able to be managed on powerful laptops, the complex calculations required to create the models have been translated into easy-to-view visual tools available to competitive sailors and maritime users.

The company at the forefront of this data modelling is Tidetech, an oceanographic data specialist comprising the world’s foremost tidal surge modelling scientists and navigation experts. Of significant note, Tidetech has been recruited to supply the 34th America’s Cup with its San Francisco Bay model.

Lead scientists Dr Roger Proctor and Dr Roger Flather have between them over 60 years of research experience with the Proudman Oceanography Centre (now the National Oceanography Centre), the world’s leading centre for tidal prediction. Dr Proctor also provided elite sailing support to the British Olympic Sailing Team at five consecutive Games between 1988 and 2008.

Tidetech director Penny Haire said races in the Solent were more often influenced tactically by tides than by wind.

“This new information is so detailed that it will show tacticians how and why one particular side of a course is favoured over another and help them to position their bow in front at the next mark,” Ms Haire said.”The south coast model clarifies various aspects of Solent currents that many competitors have found tricky in the past… for example, the model clearly shows the area of reduced tide in the lee of the Brambles Bank along with the complexities of the Hill Head region.”

“The model shows lots of areas that could well influence competitors’ tactics… it’s quite revealing, as there are areas of localised tidal acceleration that occur within very short distances.”

“Over Sturbridge Shoal and at Lepe, for example, there’s a visible half-knot variation within 100m distance and that could make a considerable difference to yachts within this range.”

The detailed information is available in GRIB format but also in an online viewer that allows any subscriber to see the relevant data on a computer, iPad or smart phone and make their own custom tidal atlas which can be downloaded as a PDF and printed for taking afloat.

Tidetech has provided data to vessels in many of the world’s biggest races and regattas including the Rolex Sydney to Hobart, San Francisco Big Boat Series, Melges 32 Worlds and many more.

The south coast model is also being expanded to cover the Dorset coastline in time for the Fastnet race.