Walking the course

Forecast for the Rolex Sydney Hobart PLUS Adrienne Cahalan gives her take on the complexities of the route

And first the forecast...

At the Rolex Sydney Hobart skippers briefing earlier Andrew Treloar, Manager of Forecast Operations of the Australian Bureau of Meteorology gave his take on the conditions competitors should expect on their run south to the south side of Tasmania.

The weather for the race will be largely dictated by a series of fronts associated with Southern Ocean depressions passing to the south of the race course and a shallow area of low pressure to the north of Sydney.

The race is expected to start on Friday (26 December) in southeasterly winds of around 10 knots that will veer to the southwest later that day. "The positioning of the system to the north of Sydney will have some bearing on the initial conditions of the race start," advised Treloar. "There is a chance it could be southwesterly by the time of the race start."

Later in the afternoon the models show the wind picking up to around 15 knots from the ESE offshore. There appears to be more wind offshore as the wind dies off in the evening and veers towards the SSE. Theleor advises that conditions could get quite choppy with the southeasterly winds opposing the northerly current.

Saturday (27 December) will see the winds veering slightly further to the SSW and building up to 20-25 knots and again against the current this is likely to be the most dangerous part of this year's race thanks to the awkward chop this will create. Further south down the course the big boats can expect westerlies or southwesterlies of around 15-25 knots across the mouth of the Bass Strait.

Saturday night the wind is expected to ease and will be lighter inshore and around the Bass Strait.

Sunday (28 December) will see the wind veered around to the northeast across the whole race course thanks to a significant front moving to the west. Crossing the Bass Strait at this time boats can expected 15-20 knots but the southflowing current tends to run out in this area so the sea state should be reasonable.

Monday (29 December) stiff northerly winds are expected to be blowing over the whole course but will drop off Monday evening - that Treloar advises competitors arrive in Hobart before Monday night!

Generally by Hobart race standards, it looks like being a light one.

Navigator and weather forecaster extraordinaire Adrienne Cahalan, who is navigator on board Andrew Short Marine (the former djuice race boat) this year gives her views on tactics for the race:

Firstly Cahalan says that the weather models for the race are all aligning and thus there is a strong likelihood that the forecast will be relatively accurate.

Despite the forecast Cahalan warns that it is possible that the sea breeze may be set up by the time of the start on Friday. "They are suggesting that because Sydney is a big city and it gets hot very quickly they say you could end up getting easterlies and maybe even a little sea breeze, but that is something you have to play by ear on the day. That probably doesn’t affect your overall strategy that much.

"When you first come out of the heads, if it is a southeasterly, depending upon how southeasterly it is, will depend upon if you take a tack or not but you would think it would be port tack and as you go down the coast and it starts to go southsoutheast then it will be the big decision as to when you tack. That will also depend upon if you are out in 2 knots of current or inshore where you get less current.

"Because it is two knots of south going current and opposing wind direction, the waves heights seriously increase to something that a lot of sailors from overseas don’t experience. Having sailed in a load of places I can say that this is some of the worse seaway in the world."

The Eastern Australian current begins in the Coral Sea and is similar to the Gulf Stream in character.

So are there advantages of going offshore? "You just have to look on the day and see if there is more breeze out there. That would be a consideration if there was. There is a quite a lot of high coastline down there particularly near Wollongong so you might get out of the local effects and get into some gradient if you go ashore a little earlier.

"Being offshore you have to be careful when the breeze goes into the southwest as well because in a southwesterly it will be hard for you to get back onshore." Ultimately getting to the finish involves sailing around the south side of Hobart and so any distance sailed to the east is ground that has to be made up later in the race.

Cahalan says that in the wind against current conditions it is vital that a boat is set up well. "So much of it comes into it in terms of preparation. If you are not prepared then you can’t with confidence make decisions. 'Yeah we are confident to slog it out in two knots of current and filthy seas'. Or 'Oh no we might have to come inshore because we are breaking the boat up'."

At some point on Saturday the big boats look set to be held up more in the transistion before the wind shifts around to the northeast. Whether the race turns out to be a 'big boat' or a 'small boat' race will depend greatly upon how long they get stuck in this.

Cahalan agrees that this Hobart race could unusually favour the 'medium size' boats as the smaller boats will run out of the wind as they approach the finish.

In Bass Strait the seaway is always the problem. Not only is it shallow, with a steep shelving of the seabed, but the waves also get funnelled between Tasmania and south Australia. Fortunately with the wind from the north it should not create too much of a problem for the smaller boats.

While crossing the mouth of Bass Strait usually sees the worst conditions, sailing down the Tasman coast is the hardest tactically. "The Tasmanian coast is the hardest place to master particularly if it is a sea breeze afternoon you can easily get caught offshore in the subsiding path of the sea breeze and get stuck in there while the boats inshore are smoking along in the sea breeze and the boats offshore are out in the gradient wind. And the coast here is very very high so there are a lot of rules like 50 miles off Mariah Island and those type of things. We won in 2000 because we stayed offshore until the very very last minute and tacked into lay the end of Mariah which is 30 miles above Tasman Island.

"But equally you can see people run inshore and watch them go inside you. And then when you get in around Tasman Island too here is very tricky. Particularly in a northeaster you can have 30 knots at sea and in there you have nothing because of the high cliffs.

"It will be northerly or northeasterly, so the wind will shut off. That’s what happened to us last year when we got passed by Grant Wharington. The year before we got caught by Assa Abloy going around the outside of us and the next year we got caught by Skandia going around the inside of us. It always helps to be the boat behind because you can see where people are parked..."

To add insult to injury the final hurdle lies in the approach to the finish up Hobart's Derwent River. "You can sit in the Derwent river when it totally shuts down with the tide running out and you have to put your anchor out. Quite often you get people sitting in the pub all night in Hobart waiting to find out whether they have won the race or not because it depends upon when the breeze fills in the next day as to how the little boats go."

To see the forecast charts see the following pages...