We will soon begin our trek across the Atlantic. The plan is to sail from Cape Town to Norfolk, VA. We plan to make a few stops along the way if time and the winds permit: Lüderitz, Namibia, St. Helena, Ascension and Bermuda.
As the tern flies, this is a distance of about 6700 nm (7705 statute miles or 12,408 km). If the tern was sailing Nine of Cups, however, the distance would be a bit more – something like 7200 nm. Often, the shortest line between two points is not the fastest or most comfortable route. For example, when Nine of Cups sailed from Ecuador to Puerto Montt, Chile, the shortest route was along the South American coast – about 2500 nm. The problem with following this route was that the boat would be fighting adverse currents and winds much of the way. On the other hand, taking a long offshore passage, added 1200 nm to the passage, but took fewer days and was a whole easier on the boat and crew.
So how do we plan the best route from point A to point B? Fortunately, sailing vessels have been plying the world for hundreds of years, and a great deal of information has been accumulated about the best sailing routes and times of year for passage making. We use several resources and references to plan our route.
Sailing Directions. This is a 42 volume reference compiled by the U.S. National Imagery and Mapping Agency that contains sailing information for virtually the entire world. The Planning Guide volumes, 4 of the 42 volumes, are especially helpful as they assist the navigator in planning an extensive oceanic voyage.
Pilot Charts. These are charts of the world's oceans, divided into 5 degree squares, that provide all sorts of useful information: Usual wind direction, likelihood of calms or gales, frequency of tropical storms, wave heights, currents and much more. The data is derived from many years of actual observations by vessels sailing the area. There is a set of pilot charts for each of the oceans, with a separate chart for each month of the year.
World Cruising Routes and World Voyage Planner by Jimmy Cornell. Jimmy has collected information from a multitude of sources and combined it into a couple of books that are well organized and extremely useful. World Cruising Routes has always been our bible for ocean passages. It provides most of the information necessary to plan a cruise or a crossing of any of the world's oceans.
Charts. We plot the actual course on paper or electronic charts, making sure there are no hazards, reefs, islands, or continents in our way.
Using all these sources, we planned our route from Cape Town to Norfolk. We won't be following a straight line. One consideration is the best place to cross the equator. The latitudes around the equator, the doldrums, are known for their fickle, light winds. The width of the doldrums varies with the season and the longitude. We want to pick a place where the doldrums are minimal for this time of year, usually further west. Once across the equator, we will be entering the NE trade winds, and to get a good point of sail, we want to be further east. A good compromise is to cross the equator at about 25° W to 30° W.
No matter how well we plan our route, however, when all is said and done, it is still just a crap shoot. This might be the year that the doldrums are widest at our crossing point, or an unseasonable early hurricane might be heading for Bermuda – perish the thought. We still need a lot of luck and the good graces of Neptune, and you can be sure we will give him a good tot of rum as we head out of Cape Town.