Much of the passage planning can be done days, if not weeks, ahead. Anticipation of the voyage can be part of the fun, particularly if you're making a passage in foreign waters. Checking the routeing is the first thing to do, along with any ports of refuge, any 'difficult bits', and of course, making sure that you have the necessary charts and pilot books on board.
The next thing to do, and it can also be done in advance, is to check the tides. Of course, if you're sailing in the Mediterranean, you won't have to worry too much once you get a reasonable distance from Gibraltar.
But with the possible exception of the Med, tides play a very important part in a safe passage plan. The first thing I usually look for is whether I'm going to encounter a tidal gate, and if so, where and when. When a tidal flow gets 'pinched' between two bits of land, or around a headland that sticks out a lot, the rate of flow can increase to the point where, if you're not going with it, you're not going anywhere! For example, if you're travelling south around the northern corner of Brittany, the pilot book will tell you very clearly where, and when, the tidal gates are.
So the first thing to do is to check the time of high water at the tidal gate, and work back from that, estimating how long it will take you from departure to get there. For any yacht over 40', I usually plan on 6 knots. Anything under 35 feet, and it's 5 knots.
The first can be a tad optimistic, the second a wee bit pessimistic, but by the time you've been sailing for a few hours, you can usually estimate your passage planning speed a bit more accurately, and adjust accordingly. Juggle around with the figures, bearing in mind that you may also have a tidal window of only a few hours for departure if you are in a marina with a sill, or if you have to lock out.
The trick is to plan back from your first tidal gate so that you don't miss it. And have an alternative ready in case you meet head winds, or no winds at all!
Using a tidal chart, if there's one available for your waters, can be a great help. But there's no beating the pencil and ruler on the passage planning chart when it comes to working out just how much time it's going to take you to get from Sunshine Marina to the tidal gate at Buggins point. Work out a few different departure times, just to see what happens - it's a great way of familiarising yourself with the route.
And don't forget to do your tidal curves. My practice, if I'm day sailing, is never to hit my bunk without having drawn in the tidal curve for the following morning, and never to sail without having noted any tidal gate 'latest time at…' on the chart.
You can work back from that if you think you're going to miss it. And don't forget to work out the tidal windows for any marinas or harbours that aren't available at all states of the tide. There's nothing worse than getting there just as the lock gates close, or you can't get over the sill. Make a note of the optimum time for departure, and any tidal gate times, on the passage plan in the log.
After a bit, working with tides becomes second-nature. Even secondary ports, if you keep at them, become fairly straightforward. If, at the beginning of the season, you find yourself a little rusty, sit down with the Almanac and work through the instructions. It's amazing how quickly the fog clears and the working out gets easy.
Do it the night before, and it's there, on your passage plan, when you need it.
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.
