Sails for Night Sailing

As the sun sets, you need to consider what sails you want to be flying as once it gets dark, sail changes become more complicated!

We like to fly our trysail and staysail overnight because if the weather pipes up, we are already reefed down as far as possible! We also like this sail plan because it is bothed balanced and low stress. Should the winds shift on us and cause us to jibe or luff, the sails are small and will not cause significant strain on the rigging.  

The staysail is easy to manage and can even be setup on a self tacker, allowing it to reside on the side of the bow that it wishes. The trysail does not involve the boom, so a nightime accidental jibe will not result in damage or strain on the traveler. 

These sails work great on beam and broad reaches, even a run (with a barber hauler for the staysail) but are not the best sailplan for beating.  A trysail is very small and low, with the center of effort focused near the mast. The staysail is a small jib and has its center of effort forward of the mast. The sails can be balanced for a windward course, but it will be a slow venture! 

If you are planning an overnight sail, consider planning it for a time when the wind will be at your backs and you can sail downwind with your tiny sails through the night without losing any speed. Otherwise, you will find your night time distance traveled to be miserably pathetic, which will prolong your time at sea as you make your passage. 

Realizing You Are Far Away

At some point, it will occur to you that you have now sailed really far away from where you started.

This occurred to us when we were in a mooring field in Fort Pierce, FL. We left Baltimore, MD to go cruising in July of 2017; and have been slowly exploring the east coast of the United States as we made our way south. It wasn't until we were tied up to a ball here that it dawned on us how far we have actually come! 

It is the middle of winter and we are sitting on the deck in our in shorts and flip flops as we watch the sun set on the horizon. We had just talked with friends and family back home and they were telling us about how the weather was getting up to the 40F's and going back down to the 30F's at night. It all sunk in that we have made it so far yet our journey has only barely begun! 

This world we live in is amazing and expansive, and what better way to experience it than from the deck of a sailboat. 

Hard Being a Dinghy

When it comes to dinghies, most people automatically think of an inflatable boat. These are by far the most common type of dinghy you will encounter, and every dinghy dock you come to visit will be packed with them.

It was such a rare occasion that we tied up at this dinghy dock in Florida next to another hard dinghy. Here in the state of Florida, you have two dinghies; one registered in Maryland, the other in Australia; tied up next to each other.

Even more special is both of us tied up to the same cleat in the same way, a bowline through the cleat.  This method of tying up allows others to tie and untie from the cleat without disturbing your dock line.

It's quite the coincidence! 

Reading Isobars

Isobars are the little lines on weather charts that tell you what the barometric pressure is across the landscape. Isobars are the demarcation line where the pressure will be the same along its entire length. 

Wind travels along the length of the isobar, and the closer the isobars are, the stronger the wind will be. Wind travels counter clockwise around low pressure systems and clockwise around high pressure systems. This means that the wind wil travel to the left or to the right along the length of your isobar depending on the location of the high or low pressure systems around it. 

While wind speed is estimated based on the proximity of one isobar to another, there are subtle variations based on line curvature. We have all had those days when they forecasted wind but it was dead calm, or they forecasted light winds and you needed to reef all the way down! What happened?! 

The answer is simple, the isobar curved in your area and altered the wind speeds. If an isobar curves inward, creating a point that the wind will whip around, the winds will be faster. If the isobar curves outward, creating a divot in itself, the winds will calm down as the transit this area and give you much calmer winds than expected. 

These isobars are extremely spaced out. There is considerable distance between each millibar of air pressure. This would tell you that the winds will be light in the entire area. Since the top of the screen has a low pressure center, you know that the winds will be moving counter clockwise or from left to right on this map. On the bottom left, you can see a high pressure area, so its winds will move clockwise or from left to right on this map. 

Now, the 1010 line makes a pronounced point, so the winds in this area can be expected to be rather higher than the surrounding areas. The 1017 line at the very bottom near 75W makes an outward turn, so the winds here can be expected to be even slower than the surrounding areas. 

Looking at the windbarb map, we can see that the winds near the point of the 1010 line are stronger, and the winds just above 75W are rather slow. 

Looking at a global map of the Atlantic Ocean, you can see a high pressure system in the middle of the ocean and two low pressure systems at the top corners. 

The high pressure system in the middle is called the Azores High, and is a famous pressure system that remains constant through most of the year. This will generate a clockwise rotation of wind around it. 

Each low pressure system in the top corners will generate a counter clockwise rotation of wind. 

The intensity of the wind will be caused by a few factors. First the high pressure area has widely spaced isobars, so the winds here will be light. The low pressure areas have very close isobars and a very drastic change in pressure from outside to inside. This will generate a very powerful wind as you approach these areas. 

The second thing affecting the wind speeds will be the curvature of the isobars. The high has relatively long and straight isobars, so the winds will be rather consistent. The low pressure systems have very tight curves, especially towards the centers. This will amplify the speed of the wind and create an insane storm! 

You can see the high pressure area is rather calm while the points and the centers of the low pressure systems are very intense.  

Learning to read the isobars will allow you to better interpret weather data received offshore via weather fax where the image is not always clear and the graphical display leaves much to be desired. 

The quality of the image depends on the quality of your signal and receiver. If the unit is not perfectly tuned, the image will be skewed. If you don't like the way your image looks, too bad! The next transmission is in 6 hours for you to try again! 

Learning to read weather maps and isobars will be an invaluable skill when cruising and you are forced to be your own weather forecaster. 

Sailing a Cold Front

A cold front, also referred to as a "storm" is a powerful wind that will reverse the prevailing winds. If your destination is upwind of the prevailing winds, a cold front is your ticket to thee fast lane!

A cold front always rotates clockwise with its winds, meaning that you can plan what direction the winds will be flowing by looking at a weather chart.  

Now, the intensity of a cold front will vary and you obviously don't want to head out in the face of a major storm! Looking at the closeness of the isobars will give you a clue as to how intense the winds will be. If the isobars are stacked closer together, you can bet on some pretty extreme wind! If the bars are spaced well, the winds will be lighter.  

As a cold front approaches, you want to plan on leaving as the 1020mb line approaches. This will give you good winds and a nice passage as you make your trek with the winds. 

With your passage planning, it is important to keep in mind the sea state. Waves form because of the winds. The stronger the winds, the taller the seas. Mature waves, however, need a lot of distance and some deep water to form. If the winds are blowing off the shore and onto the water, the fetch wil be less and so will the height of the waves. The other aspect to keep in mind is the water depth. If the water is shallow, waves will crest and break long before they reach their mature height.  

In winds of 30 knots, mature waves can be around 20 feet tall, but if you are in water of 30-60 feet in depth, the waves will top out at around 6-8 feet in height. This will give you the power of the wind without the uncomfortable motion of a tall sea state.  

The duration of a cold front will vary, so it is important to study all available inlets between you and your destination. This way, if the weather becomes something you do not want to endure, you can sneak into the next available inlet and escape. Also, if the winds shift or the cold front passes over you before you get to your destination, you will know where you need to go to wait for the next favorable front to continue your downwind sleigh ride!