Tuesday, 26 November 2013

The waiting game.


We call it ‘waiting for the weather’. It’s a phrase that we use often, in texts to family, in a facebook status and in conversations with other boats. It trips off the tongue easily but means so much more than those few words actually say. Wind speed, wind direction, gusts, currents, swell, wave height, wave distance, precipitation, electric storms, visibility – all those things have to be taken into consideration. Get one of them wrong and it can put a severe crimp in your day.

The wind needs to blow the right way for sailing boats. You cannot sail a boat directly into the wind.  If the wind is coming straight at you have to either turn on the engines or tack (go in a zig zag) which can add miles and hours on to your journey.

The right strength of wind is important. Not enough and we have to motor all the way which is not the nicest way to make a trip although most cruising boats apparently motor about 50% of the time. Too much wind and it becomes dangerous. There is a rule of squares which means that for every doubling of wind speed the force on the sails quadruples so strain on the boat and the sailors is increased by four times (the square of two), triple the wind speed and the forces multiply by nine times. We’ve been out in force 6, the skipper has been out in force 9 but it’s not a good thing to do with your entire house and family.

Short wave length - very choppy.

Then there are the waves. For us they have to be below 2 metres, that is a figure we set ourselves after a few scary trips. Waves slam into the bridge deck, things bang, the boat shakes and flexes, moving around is difficult and it is not pleasant.

And there is also the wave distance to consider, if the waves are close together it is nasty. With big gaps between each wave it can be an interesting trip gently riding up and down the hills and valleys especially when all you can see is water above you in front and behind.

Sometimes you have to wait for the water. This is known as a tidal gate. sometimes the tide has to be right before you can leave somewhere, other times it has to be right to enter somewhere, other trips it is both the start and end which makes life quite exciting trying to get the timing right. There are also harbours which have locks or sills which rely on there being the same amount of water on both sides. These things are more common in Brittany where the tidal range is so big. The other problem with tidal gates is when you are planning a longer trip. If you are restricted to when you can leave it can mean arriving at the next port at an awkward time of day.

The notorious Portland race, Dorset, England.

Then there are currents, the strength and direction are important in deciding between a good trip, an uncomfortable trip or a dangerous trip. We have come down some rivers at 2-3 times our normal speed pushed along by the currents. Now imagine the same current pushing against you. In the races of Raz de Sein and Portland a current against you or against the wind becomes very dangerous making timing really important – there is just a 15 minute window of error for the Raz, quite a challenge if you are coming from over a hundred miles away – which we did heading north.

Every boat has their favourite weather report and most use 2 or 3 so that everything can be compared to get the best chance of a reliable forecast. As a cruiser you live with the weather all the time and learn, very quickly, what the limits of your boat and crew are. There are always things which can be done or seen ashore whilst waiting for the weather, taking a chance with the house and family just isn’t worth it.


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