WEATHER CONTRIBUTED BY SIMON ROWELL, ROWELL YACHTING SERVICES THER WEA Becky Walford Local effects around the Island The waters around the Isle of Wight, as well as being an excellent playground for all sorts of on the water activities, also have a wide range of local land features that change the flow of water and air around them considerably. It’s worthwhile thinking about these when you’re planning on going out and about. Constrictions and Guides When fluids are set to flow through smaller gaps or close to directional funnels they tend to move faster then fan out at the other end. Starting off at the Needles Channel this is most obvious with the tide, particularly on a spring ebb. It piles through Hurst Narrows, making a fine job of dredging it out to be on the deepest part of the Solent, and then rushes through the channel between the Shingles Bank and the Island before causing a standing grave over the Bridge coming off the Needles themselves before dispersing into the Channel itself. With the wind through Hurst Narrows it’s best seen with a strong SW, which will tend to flow faster in the gap between the higher island and the New Forest before tending to funnel more WSW up the Western Solent before spreading out slightly into the Central Solent. With this wind direction the Eastern Solent is often more sheltered and a little patchier – so the effect of the channelling up the Western Solent turns what is a good solid SW all the way along the windward south coast of the Island into 3 quite different wind regimes on the leeward north coast. Similar effects occur with different wind directions – with anything from WNW to NNW winds this will get funnelled down Southampton Water before spreading out into the Central and Eastern Solent. It doesn’t need both sides of the flow to be contracted either, as anyone who has sailed close in round St Catherine’s Point in a strong W will attest. The flow around that will be accelerated to bring a much stronger local wind than that which is a couple of miles south of the Island. The effect on tide there is well known too, with the charts showing over falls on both the ebb and flood around the underwater profile of the point. 22 solenthandbook.com