| At Sea. Merry Men of Mey first challenge for Volvo Ocean Race fleet in notorious Pentland Firth |
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| Wednesday, 07 June 2006 | |
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Marian Martin The Pentland Firth is a narrow channel, averaging 6 to 8 miles wide and 14 miles long, which lies between the Scottish mainland and the Orkney Islands and links the Atlantic and North Sea. For centuries, historians have told tales of its dangers and the wrecks that lie there; John of Fordun wrote, in 1380, that “Scotland is bounded on the north by the Pentland Firth, where a fearfully dangerous whirlpool sucks in and belches back the waters every hour.” The Firth’s reputation, as one of the most dangerous stretches of water in the world, is well deserved, for it is an area notorious for maelstroms, very strong tidal streams (up to 16 knots have been recorded) and more than its fair share of winds in excess of Force 7. It is very unlikely that the Volvo Open 70s will experience strong winds, if they elect to take this “short cut”, but light airs and fickle winds can also produce hazardous conditions and, a combination of foul tide and no wind could make the short cut very long in terms of hours. The tides meet a number of headlands, islands, islets and sandbanks, which results in eddies and races that – even in calm weather - can be very violent and can occur with no warning. Going from the main stream into an eddy can cause even large vessels to sheer violently, so the yachts will have to give all the islands, headlands and other dangers as wide a berth as possible, especially if they pass through at night, or the visibility is poor. Just what conditions and hazards the yachts will have to cope with will depend on their time of arrival: Merry men of Mey The first hazard for any yachts taking this route could be the largest and most dangerous race in the entire Firth. The Merry men of Mey forms, off St John's Point, during the west going tidal stream and grows to extend across the entire width of the Firth. When the west going stream has attained its full strength, heavy breaking seas can extend the whole way across the firth, between St John's Point and Tor ness even in fine weather. The Merry men of Mey race is most violent where it crosses a large sand wave field, about 3 ˝ miles west of Stroma. Stroma There is a choice of routes here; the Outer and Inner Sounds. East going tidal streams are very strong through the Outer Sound, the stream beginning at a rate of about 9 knots. In the Inner Sound the easterly stream runs at about 5 knots and eddies are generally weaker than those in the Outer Sound, so this may be the favoured route. Off Swilkie Point there is a whirpool, where the main streams through the Outer Sound meet north going eddies. The Swilkie is almost always present and needs to be avoided even in fine weather. Pentland Skerries Off the numerous islets, known as the Pentland Skerries, the Volvo Open 70s are quite likely to encounter a tidal flow rate of 12 knots. Duncansby Race This race forms to the west north west of Duncansby Head when the south east going tidal stream begins, creating turbulence off the Head throughout the entire period of the south east going stream. The above are just the main challenges that the fleet face, there are numerous other outfalls, eddies and maelstroms and an additional hazard is a near continuously changing bottom profile. |
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| Last Updated ( Wednesday, 07 June 2006 ) |
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