Whilst most of your passage planning can be done in advance, the weather is something that you have to check, and keep checking. In our technologically advanced society, and particularly in home waters, there really isn't any excuse for anyone putting to sea without a good understanding of what the weather is likely to do.
I say 'likely', because, even with the best forecasting service and the most diligent skipper, it's possible to get caught if the wind is stronger than predicted, or the front arrives a lot sooner than expected. But the risks are minimised if we take care to check the weather first.
Listen to the inner voice. Putting to sea on a gloriously sunny morning, with a brief glace at the Navtex, but with that nagging doubt at the back of your mind that you're not quite sure what the weather is predicted to do, is a warning sign. It pays to check. Most of us grew up playing the game of listening to the early morning shipping forecast - if we remembered to get up in time.
With today's forecasting, it's possible to get a fairly good idea of the weather patterns up to a week in advance of the passage. I am a great fan of the European Community Medium Range Weather Forecast, and regularly refer to the medium range deterministic forecast that they provide free of charge.
You can find it on their website at www.ecmwf.int and in my opinion it's quite superb and surprisingly accurate. I shall never forget the prediction of strong winds in Mallorca at least a week before we went out there, and sure enough, we were holed up for three days just as predicted. I can usually get a view about the weather at least seven days in advance, and sometimes, in settled conditions (not recently found in the UK) even more.
There's no substitute for learning how to read the synoptic charts. It's not easy (at least, I had to struggle with it), and time spent at evening school with a meteorologist is a great investment. If you're like me, after a bit you begin to get a feel for it, and you'll soon be looking at the patterns of weather fronts and the progress of low pressure systems and muttering about occlusions and high pressure bridges in your sleep!
Another great innovation is the Grib chart, based on wind spikes. They've been around for a long time, but the ability to get them free, direct to your laptop, hasn't. I use the UGrib software, and on my last passage around the coast of Spain it proved remarkably accurate.
So you've checked the routeing and the tides, got a feel for the weather from the medium range forecast, listened to the shipping forecast that morning, and got your kit and your crew on board. Now is not the time to relax. The weather can change, and we need to keep on top of it.
And thankfully, we have plenty of options for getting weather at sea. Navtex is brilliant in my view (but you have to have left it running for 24 hours before you need it), and you can listen to the coastal radio stations' weather forecasts. I connected my laptop to my mobile phone on the last foreign voyage, and got the Grib charts whenever I was in range of a mobile phone signal. It was brilliant!
If you plan to visit foreign waters, spend a few hours checking on weather sources before you leave the UK. If you have the internet (and if you're reading this online, you probably have), it's worth checking on one of the bulletin boards for people who are sailing in the waters you intend to visit, and asking them where they get their weather information.
Navtex usually comes out tops in the western Mediterranean, closely followed by VHF. But the great joy of chatting on the internet with local sailors is that they can give you local knowledge. There are some places where the wind regularly gets up in the afternoon, blows hard for a few hours, then dies down in the evening - whilst the Navtex gives a steady Force 3 and the barometer stays absolutely flat!
Once underway, make sure that the crew are instructed to read the barometer and note the reading in the log every hour. If it changes, as it will, try to understand the pressure movement against the synoptic chart. It's not so much the fact of change, as the speed of change, that's important.
If you are sailing at six knots in one direction, and a weather system is coming in the opposite direction, you can sometimes see quite a remarkable movement in pressure. It can predict a blow more accurately than the forecast, so be prepared. And beware of any change when you get to the eastern end of the Med!
I once sailed with a couple fairly new to sailing, and asked them to make sure they noted the barometer reading in the log. Standing in the cockpit in the glorious sunshine, they looked decidedly puzzled, and one of them told me that on their sailing course they had been told that no-one used barometers any more.
I was able, later that very day, to point to a rapid fall in pressure, relate it to the synoptic chart, and sure enough, by the late afternoon we were sailing in strong winds and enough rain to shut visibility down to almost nothing!
Good passage planning is about the avoidance of nasty surprises, and while it's certainly possible to get caught out by the weather, making sure you keep a check on the weather is the best way to avoid nasty surprises in the wind department.
Richard Thomas holds a Commercially Endorsed RYA Yachtmaster and Cruising Instructor (Sail) certificate. He runs his own delivery business, www.yachtmovers.co.uk
He is available for deliveries, assisted passages, own-yacht tuition, and yacht management.
