Rick Tomlinson / Volvo Ocean Race
Both the start and the finish lie in the belt of east-going low pressure systems and these, along with the Gulf Stream should dominate the tactics ...
Friday 15 May 2009 14:00 GMT
By Mark Chisnell
Leg seven: Boston, USA to Galway, Ireland across 2,550 miles of the North Atlantic. It is to ocean racing what the E-Type Jaguar is to motor cars – a classic. It was a trans-Atlantic race that really began the sport as we now know it.
Way back in 1905, the hard-driving, three time America’s Cup winner, Charlie Barr, won the Kaiser’s Cup on the schooner Atlantic, setting the record at just over 12 days. That’s not a bad race time in a mono-hull even now, but hopefully, the Volvo Open 70s will be doing it a little quicker than that. Or they’re going to struggle to get ready for the in-port racing in Galway.
In all the previous leg previews we’ve used the idea of crossing or transiting along climate zones. And since this is the last chance before we quit open ocean racing for the coastal variety, we won’t do it any differently this time. Both the start and the finish lie in the belt of east-going low pressure systems, and these, along with the Gulf Stream, should dominate the tactics of leg seven. Both are headed for Europe, just like the boats, but both need to be handled very carefully to extract the best from them.
But there are also a few obstacles in the way, as Riath Al-Samarrai outlined in his report on the Team Ericsson navigation briefing earlier this week.
If the number of boats out watching the in-port racing was anything to go by, the obstacle course could start early if the spectator fleet isn’t disciplined. So long as the conditions are right, the fleet will race a lap of the harbour after the start off Fan Pier. A light sea breeze is forecast for Boston harbor by Matt Sanders, the Assistant Race Meteorologist. Matt reckons it will come in from the east-southeast between six and 11 knots before midday, trending to the south-east after 13:00 (local time). That would mean the fleet sailing upwind on the final leg out of the harbour, before exiting to the north-east. So long as they don’t hit any spectator boats, (if you follow the link, it’s about half way through, listen for the immortal words, that’s all right, hold the course…).
The next thing for the boats to avoid is the same whale exclusion zone that they had to sail around on the way into Boston. The first leg along the north-west side of the whale box should start out as a reach in the south-easterly sea breeze. The wind is forecast to veer (rotate anti-clockwise) to the south, and build a little on Saturday evening, because of a low pressure system approaching Boston from the west. That means that they may get a chance to do some sailing with the spinnakers up, before they reach the top of the whale box and head out into the Atlantic.
Once the fleet is clear of the whale box, the initial tactical target will be the scoring gate for this leg – the first boat to leave the island of Newfoundland to port and cross the line of longitude, 52 degrees 38 minutes west, will pick up the maximum four points. So the initial race will be due east, and not just because of the scoring gate. The fleet must also stay south of an ice exclusion zone around Newfoundland. This is different to the ice gates that operated on leg five. This time around a box has been defined that the fleet cannot sail into – you cross the line and enter the box, you break the rules, simple as that.
The southern limit of the box is positioned at the southern tip of the Grand Banks. This is where the cold water of the Labrador Current, which carries the ice down from the Arctic, meets the warm water of the Gulf Stream. It’s notorious for fog and bad storms, as well as ice bergs. In fact, The Perfect Storm of literary fame occurred here. It’s a good place to stay away from.
The ice box will be illustrated on the Race Viewer when it’s loaded and ready for the start on Saturday. But if you want to take a look at all the coordinates now, then you can download the leg sailing instructions right here. And if you want to check out the latest data on ice bergs in this region, then this link will be useful.
As I mentioned earlier, the strategic game in the race to the scoring gate and then onto Galway will be to maximise the advantage from the weather and the Gulf Stream. We talked a little about the Gulf Stream on leg six, when the fleet had to cross it to get to Boston. This time around they will be trying to find the main east-going flow to ride to Galway, and to dodge the counter-currents and eddies that are trying to take them back to Cape Hatteras.
The game with the east-bound low pressure systems should also be familiar by now, as the principle is the same as in the Southern Ocean. The key difference is that the wind circulates anti-clockwise around a low pressure in the northern hemisphere, and so the favourable westerly wind is to the south of the centre, as the low pressure travels from west to east. That means that the fleet doesn’t necessarily want to follow the shortest, great circle route in the far north, but it will depend on the path of the low pressure.
But if you’ve already taken a look at the weather charts for the North Atlantic for early next week, you may well be asking yourself - what low pressure? So much for the general theory of trans-Atlantic racing, right now the picture looks a little different for the first few days of the leg.
The low pressure system approaching Boston from the west (and providing the building southerly breeze for Saturday evening) is forecast to stall inland. And once the fleet clear the whale box and turn east, they will be sailing out into a ridge of high pressure extending beyond Nova Scotia. Initially, the combination of the low with the high pressure sitting offshore will set up a solid southerly wind, providing some pretty fast reaching conditions through Sunday and into early Monday morning.
After that it gets a lot trickier as they get further into the high – this weather feature is forecast to continue to dominate the picture through most of next week, and things could slow right down. And with low boat speeds, the relative importance of finding the three or four knot advantage that the Gulf Stream can provide will become more important.
But the skippers and navigators must be careful that in chasing the Gulf Stream, they don’t position the boat badly for the arrival of a new, stronger breeze - or the leaderboard will be a real rollercoaster through next week. The strategy must be to balance the gains made from the eastward flow of the Gulf Stream against those to be made from the weather. But that’s why they have all that fancy software on board, and that’s why we have our Predicted Routes on the Race Viewer.
We’ll get our first look at those in Sunday morning’s TEN ZULU, by which time the fleet should be past the whale box and out into the Atlantic. The picture should be much clearer by then, and we’ll see what sort of weather is shaping up for the rest of the trip across.
At 10:18 16 May 2009, Gavin Cooke wrote
Hi,Why do you always refer to Ten Zulu as being in the morning?With a world wide race and audience - for most of us (including the racing fleet for 80% of the race), Ten Zulu is not in the morning!It got very confusing when the fleet were in Asia as sometimes you referred to something happening in the morning and the reader couldn't be sure if you meant in the morning for the fleet or in the morning for the author.Otherwise, keep up the good work.Gavin Ten Zulu in the evening.
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