The wind was up and down
Wind gusts that would go virtually unnoticed by those walking around on land can play havoc to those traveling on a sailboat. This we know from experience! As I wrote in the last post, it was a big wind gust that caused the damage to our boat on Friday. We had an equally gusty day on the water yesterday, making for a sometimes exhilarating, and other times frustrating, sail.
When wind increases in velocity, the force exerted on a boat’s sails increases exponentially. As an example, a 20 knot wind applies four times the force that a 10 knot wind does. Yesterday, we frequently saw the wind drop to less than five knots. In fact, we were stopped dead in the water on multiple occasions, drifting with the current. Just as often though, the wind would suddenly jump to over 20 knots, the highest we recorded was 29.2 (true, not apparent). Fortunately, after the trouble we had the previous day, we had the foresight to begin the day with our mainsail reefed and only our little jib flying.
Although this is the lowest wind velocity I snapped a pic of, there were several times when we had no wind at all!
Our gauge recorded 29.2 knots as the highest but both Rebecca and I both saw it gust to 29.8 for a few seconds.
Why is the wind so gusty here? I’m nowhere near an expert on weather conditions but I’m going to speculate a bit. If I’m wrong, feel free to call me on it.
The high mountains along the coast no doubt have an effect on the wind here. Even though we were sailing on the protected side of the island (the trade winds blow from the east and we were sailing on the west side of Guadeloupe), they say that the wind on the lee side is effected by the land for a distance of seven times the height of the land mass. In other words, if the hills along the coast were 500m high, and many of them here are quite a bit higher than that, we would need to be 3500m offshore before we would have wind free of the land’s effect. At times strong winds can flow down off a mountain slope, much like a stream of water runs downhill. The name for this effect is Katabatic and my guess is that at times, this is what we were experiencing.
In addition to the land effect, the sky yesterday was littered with big, puffy cumulous clouds, some of which were quite dark and carrying rain. We have learned from past experience that the wind often increases sharply when passing underneath clouds like this. Yesterday proved to us again that this can be true.
Rain in the distance as we tack in towards the shore. We tacked again to avoid all but a sprinkling.
As I said, gusty conditions are definitely not favorable for the cruising sailor. Sails can be set for either light winds or strong winds but when the wind velocity changes abruptly, especially when it increases due to the effects I described or for other reasons, it can cause problems. In our case yesterday, it meant that we had to hand steer for the entire trip, and consistently be on our guard. It was not a relaxing day of traveling.
Like.. Relevent, interesting and consistent. Like your approach to sailing, admire your sense of adventure, appreciate your consistency. Keep it coming. You are an inspiration for me and I’m sure many others.
Thanks very much, Robert!
If it was smooth sailing every day you’d get bored! Being the experienced sailors you are now you can handle most anything! Is there any good snorkeling around Guadelupe? How long do you think you’ll be there and where to next??? I know….. plans are made in sand.
We definitely deal with adverse conditions and situations WAY better than we would have even a year ago.
We haven’t done much snorkeling these days although there definitely are some good spots. We are currently in the Saints, having left mainland Guadeloupe. We “might” head back there, if the conditions lighten up (we had huge waves and gusts to 36 knots on our sail here).
That’s one of my biggest concerns with a cat. Clearly the winds effect all boats but a cat on autopilot in unpredictable gust can end up in a dangerous situation. I know is very rare but I’ve read a couple accounts of capsized cruising cats. In every case it was determined they had left the autopilot engaged.
Be safe out there!
I would like to read about those capsize situations if you have some links, Geoff. I would also bet the cats in question were over canvased. We tend to reef pretty conservatively.
Capsize of Atlantic 57 Anna
http://www.chriswhitedesigns.com/news/anna_capsize/index.shtml
http://www.syanna-kellywright.com/
Fair Winds, Following Seas, Good Anchoring, and plenty of ice cubes,
RayG
Excellent link! Thank you.
Hand steer?!?! Oh you poor thing. 😉
You’ll have Zach to steer for you.
And Happy Birthday, Cindy. 🙂
speaking of wind and clouds…
Last August, in Indiana, USA at a state fair, a storm blew through wrecking a stage and killing a few people. The organizers/weather people were paying attention to the storm itself but missed a key aspect of how storms cause additional winds. The rain pouring out of the clouds pushes the air beneath the clouds out, creating a wall of wind several miles out in front of the storm. The lesson: the effects of a storm are bigger than they look on radar (might explain a some of the phenomenon you described.)
P.S. I’m first time poster, having caught up on the whole archives over the past few weeks. +1 to the suggestion of figuring out a better way of reading the archives… I’m pretty sure I started reading before the newish “start from the beginning” image, and ended up hunting the last (first) page… page 107 at the time. Still, love the blog and hope to see you on the water some day.
Hi Ben. Thanks for taking the time to post. I definitely agree that the wind proceeds the storm. We experienced that the day before yesterday during our sail from Guadeloupe to the Saints.