Passage planning is fun and very rewarding when you get it right, for a successful passage plan the acronym KISS (keep it simple stupid!) springs to mind. Seriously though, don’t make it unnecessarily complicated.

Weather - Firstly get a weather forecast for the area in which you plan to sail, if the wind is going to be strong (say more than force 5) and from dead ahead meaning that you are going to be beating to windward all the way perhaps a decision to either delay the passage and wait for a fair wind would be the most sensible thing to do. Or if you can’t wait then sail somewhere in a different direction where you will have a fair wind at least most of the way. Remember sailing is supposed to be fun!

Having decided that the weather is suitable for your passage then measure the overall distance of the passage by walking your dividers at a set distance of about 10 miles along the route. Divide that distance by the speed that you think your boat will achieve over the ground and your answer will be the hours that the passage will take. For instance a distance of 90 nautical miles divided by a speed of 6 knots will take 15 hours.

Food - The next question is do you have enough food on board to feed yourself and the crew for the duration of the passage, it is a good idea to have a proper meal just before you leave and then plan for two more during a passage of 12 to 15 hours.

Crew - Another question you should ask yourself is do you have sufficient crew and are they experienced enough for the length of the passage and if the passage is going to be more than about 8 hours can they stand a watch while you are off watch below.

Tidal Gates - Now you need to consider ‘tidal gates’, this will involve studying one or more tidal stream atlases to find out if there are any headlands or narrow channels when you can expect to experience a strong tidal stream. Whilst you can buy tidal stream atlases for most areas where you can expect strong tides, there are all that you need in Reeds Nautical Almanac which you can buy from any chandlery or online bookshop.

Beaulieu River to Victoria Marina at St Peter Port - Take for example a passage that you are planning from the Beaulieu River in the Solent just to the west of Southampton to Victoria Marina at St Peter Port in Guernsey in the Channel Islands. From your first look at the chart you will have seen that you may have two tidal gates, firstly the Needles channel at the western end of the Solent is likely to have a strong tide because it is so narrow at Hurst Castle and secondly if your planned route is going to take you between Cap de la Hague and Alderney which is the most direct route, there is likely to be a strong tide there, particularly when you notice from the chart that that stretch of water is actually called the Alderney Race!  Click here to see a google satellite photograph of the whole passage.

A quick look at the tidal stream atlas for the Solent (page 220 of Reeds and please note that these chartlets are relative to HW Portsmouth) and you will see that if you try and sail down the western Solent and the Needles channel at the wrong time you could experience as much as 3.9 knots of tide against you (foul tide). This would mean that the distance of 12 miles could take you almost 6 hours even sailing at 6 knots through the water, because you would only be actually achieving 2 knots over the ground. However sailing with the tide will take only about one and a half hours because you could be achieving 8 or 9 knots over the ground. Click here to see a google satellite photograph of the western Solent - The Beaulieu river is just to the west of Lepe in the top right hand corner and Hurst Narrows at the beginning of the Needles Channel is at the bottom on the left.

You now need to look at the tidal stream pages of Reeds for the Channel Islands (page 808 – please note that these chartlets are relative to HW Dover) to see when you will have a fair tide in the Alderney Race.  A quick look at these two pages will show you that if you get your timing wrong here you could have as much as 9 knots against you, this won’t just slow you down, you will be going backwards!  You will also notice that whilst the tide is very strong in the Race it is also quite strong all the way down to St Peter Port a total distance of about 20 nautical miles.  This ‘tidal gate’ is even more important than the one in the Needles Channel. So the whole passage plan is going to hinge on having a fair tide from the Alderney Race down to St Peter Port, which could take as long as 3 hours.  To see a satellite photograph of the passage from the Alderney Race (just to the west of St Germain de Vaux) down to St Peter Port click here

Just in case your passage across the channel involves your taking longer than planned make certain that you plan to arrive just to the north of the Alderney Race when the tide turns to running in a southwesterly direction.  If you look at the chartlet for HW Dover on page 808 you will see that the tide has started running in your favour in that hour, and so plan to arrive at the beginning of that hour which will be 30 minutes before HW Dover. Looking forward now to the hours shown for after HW Dover you will see that the tide will continue in your favour until about 5 hours after HW Dover which should be plenty of time to sail down to St Peter Port.

Now that you have decided on the time that you want to arrive at the Alderney race, measure the distance across the channel to the Needles channel which you will find to be about 65 miles, at your planned speed of about 6 knots this going to take around 11 hours.

Now go back to the tidal stream atlas for the Solent and see if you will have had a west going tidal stream there during the period 11 and 12 hours before your planned arrival at the Alderney race. The answer to this question is yes and so you now know that you should weigh anchor in the Beaulieu river about 12 hours before your planned arrival at the Alderney race.

Tidal Heights - The next question is will you have enough height of tide to get out of the Beaulieu River at that time as you will have noticed from your pilot book that there is only 0.7 meter on the bar. So you now need to look up the time of high water at Stanmore Point (the mouth of the river) and you will see that it is a secondary port on Portsmouth. You won’t have to do any calculations here because you will see that your planned departure time is very close to high water so there will certainly be enough water when you leave.

You will have noticed from both Reeds and your Pilot book that times of entry into the Victoria Marina at St Peter Port are restricted as a result of there being a sill at the entrance to the marina to keep the water inside.  This sill has a drying height of 4.2 metres above datum, you will therefore need to add the draft of you boat to that figure and then complete the tidal graph for St Peter Port (Reeds page 818) to work out when you will have enough water to get in. If there is not enough water over the sill when you arrive, you will see from your pilot book that there is a waiting pontoon in the outer harbour where you can wait until there is enough water for you to get over the sill and into Victoria Marina.

Pilotage - You will need to look down your planned route to see if there are any parts where you will need to do a pilotage plan and if so you will need to use large scale chart of those parts of your  passage and / or a Pilot book. On your passage to St Peter Port there are three, firstly a short plan to get out of the Beaulieu river, then another for the Needles channel and thirdly the approach to St Peter Port which is known as the Little Russel. A simple pilotage plan for these three stretches of water will take all the stress out of the beginning and the end of this passage plan.  To see a google satellite photograph of the Little Russel click here

Ports of refuge - You must consider as to where you can go if anything should go wrong with either the boat or perhaps in the event of one of the crew being ill or injured. Make this decision in advance for each part of the passage in your plan. Once you have cleared the Needles the tide will be too strong for you to turn back and so your only option will be Poole.  As you sail across the channel providing you have a fair wind you will have the option to turn back, but once more than halfway across you only ports of refuge will be Cherbourg or Bray Harbour at Alderney, if you are going to use Cherbourg you need to make the decision at least two hours before you reach the Alderney race otherwise you will have a strong tide against you. Alderney is a good place to go to as long as the wind isn’t in the north east when it becomes an uncomfortable place to be.

The passage plan described above is one where having got the timing right you can sail continuously from the start at the Beaulieu river to St Peter Port without experiencing a foul tide. Not all passages are as easy as this one. Often when planning a passage along the coast, you will find yourself unable at some stage to avoid a strong foul tide for up to 6 hours round a headland or in a narrow channel; rather than struggle into it achieving little or nothing over the ground it is better to plan a stop at anchor or even go into a harbour and have a meal on board or ashore and catch up on some sleep and then carry on with your passage when the tide is once again in your favour. Tom Cunliffe's Channel Pilot shown at the top of the page is an absolute must for cruising in the English Channel, you can buy it from any chandlery in Britain or online from most online bookshops.

Courses to steer - Finally the only subject that I haven’t covered is ‘courses to steer’, these I feel should be done as and when you need them during the passage as it is only then that you will know your speed, the time, direction of wind and tidal streams.

My thanks to Mike Paget-Tomlinson for the four photographs above taken in the Little Russel in April 2010. My thanks also to Tom Cunliffe for his permission to use the picture of the cover of his new Shell Channel Pilot and also thanks to Adlard Coles for their permission to use the picture of the cover of their Reeds Nautical Almanac.