One of the keys that the navigator must have with him is the one that opens the door to the knowledge of meteorology. The path to achieve the appropriate notions that make us independent or in any case adequate to understand the wind and the sea through the analysis of weather maps (synoptic) is mandatory, in our opinion.
Apart from reading books and manuals, I highly recommend taking specific courses, from basic to advanced ones. My experience as a student began years ago by enrolling in my friend Meggiorin’s Navimeteo courses. First basic courses, then gradually dedicated to the Atlantic Ocean.
Now that we have the organization of the circumnavigation in our heart, we are already organizing courses for the Pacific and the Indian. Each sea has its own history and its own meteorology.
Now it is not in the ropes of this book to replace the masters, but it must be kept in mind that a good knowledge of this subject is as important as that of your boat and safety at sea.
Let’s talk about the Atlantic Ocean.
The Azores anticyclone is the sole governor of weather conditions that will guide sailors both to the Caribbean and back from the Caribbean.
Together with the anticyclone, the minor actors participating are the low pressures that depart from the United States to reach the Mediterranean and that can, depending on the time of the year, rise or fall on their way, making the anticyclone move, disturbing it and creating areas of perturbed instability.
First rule: choose the correct season and absolutely avoid seasons at risk of violent and dangerous phenomena.
Outbound to the Caribbean: from mid-November to February (although it can be traversed until April / May) but it doesn’t make sense because when you get to the west the hurricane season begins.
Return from the Caribbean: May to July. Do not postpone your departure from the BVI or Bermuda beyond the end of May due to the risk of incurring potentially violent phenomena.
It goes without saying that the return has a shorter window and is much more technical, fresher and must be planned with extreme care.
The outward journey is characterized by the exit from the Canaries to go south, towards Cape Verde, towards the famous “Colombo gate” (25 ° south 25 ° west) where you can turn decisively west, and where, theoretically, the famous “Trade winds”, the trade winds, or the outer edge of the Azores anticyclone, which carrying winds in a clockwise direction (let’s imagine it as a huge gear that turns clockwise, being a vast area of high pressure), the boat that goes towards west must engage the outer wheel gear and be taken to the Caribbean. The real problem of the first leg is getting to hook these winds. In fact, the exit from the Canaries can be complicated as a low pressure that persists is established in the north of the Canaries (counterclockwise wheel and disturbance and destabilization of the anticyclone), brings winds from the south west on the Canaries, or on the nose for those who starts west. I guarantee you will not pass. Our second crossing we chose to do it in January convinced that we would find trade winds more stable and less influenced by these low pressures…. We were in Tenerife waiting for the departure of the Caribbean Odyssey scheduled for January 10, 2017. From December 28 to January 9, winds blew constantly from the southwest! A different departure would not have been possible.
You will have read or read from the diaries that even the first crossing that started from Lanzarote forced us to a forced stop in Gran Canaria because the 40 knots from the southwest did not allow us to continue safely. From these lines another truth arises: sailing with carrying winds is a rule that must always be followed. The forced windward for days is devastating for the boat and for the crew and should be avoided when possible, and if inevitable, the boat wins, it must be adequate, robust and with a powerful hull design and designed to gently go up the sea even if strong and contrary. In this regard, we have chosen Hallberg Rassy to navigate the ocean in all conditions. The German Frers pencil is a guarantee in this sense. Returning to the meteorology of the first leg, the most complicated part is managing the first 500/600 miles trying to reach the main winds as soon as possible.
Once placed in the middle of the trade wind we must be careful of the so-called squalls, or groppi in Italian. Violent phenomena that usually follow the carrying winds, and are accompanied by rain and reinforcements of 2/3 wind forces, last for half an hour and then overtake you and go away. During the day you can see them, and at night you have to sharpen your senses: when in the cockpit you feel fresher and more humid air with micro sprays, not rain, like a strange mist, hurry to reduce the canvas, and take a look at the radar to quantify its extension, speed and direction. As lat