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VOL. 12 NO. 10
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Handling your boat in wind

Wind can be hard to predict and harder to handle

Handling your boat in wind

Of all the challenges boaters face, wind is the most difficult to prepare for. In some locations, winds can be predictable at times. Local sailors have learned how to control their vessels in these conditions, but the same winds can be frustrating and dangerous for inexperienced or visiting boaters.

Predicting wind
Unlike storms, currents, tides and fog, wind is difficult to predict accurately. Of course, wind just doesn’t show up unannounced. Meteorologists can track the high and low-pressure systems that drive winds, using widely available maps showing isobars and compression bands, but the accuracy of general wind direction and speed predictions can vary from location to location.

How wind affects piloting offshore
You don’t have to be a scientist to understand the effects of wind on a ship. Offshore areas have more predictable winds than coastal areas, making their effects on operations less significant. Most wind concerns offshore have to do with wave action. Offshore buoys and weather stations do a good job of transmitting sea conditions in real time, and the pilot can anticipate changes in sea state by keeping a close eye on the instruments. A good pilot considers wind direction and how a change in direction impacts fetch. Fetch is the distance a prevailing wind travels over open water before reaching shore or a vessel.

For example, if an offshore wind is blowing, the distance from the shore to the vessel is equal to the fetch of the wind. This is important because energy is transferred from the wind to the water surface by friction. The longer this friction takes place the larger the wave that forms. As larger waves form, friction increases and builds bigger waves.

Strong winds dictate what course should be steered. Even large ships must steer into the oncoming wind to avoid the side-to-side motion called wallowing. A wallowing ship is uncomfortable to be aboard, so always keep wallowing to a minimum to help minimize seasickness and keep passengers comfortable. Heavy rolling can also cause cargo to break free or shift.

How wind affects piloting near shore
Winds near shore are a serious safety issue. Shallow waters can drive offshore swells into steep waves. Rocky shoreline or concrete face walls reflect this wave action, causing multi-directional chop that can exceed the height of the original waves.

Wind also makes it difficult to maneuver in channels and harbors. Geography and structures may block some winds but funnel others to much higher speeds.

Large ships have the help of tugboats when operating in these areas and may choose not to enter a harbor until conditions have improved.

Smaller vessels don’t have as many options in windy conditions. It’s miserable to wait outside a harbor for hours while the vessel pitches and rolls.

The most precarious situation is to dock in winds that are blowing perpendicular to the face wall or dock. An offshore wind causes quite a bit of frustration as you are blown back off the wall several times, causing you to attempt landing again and again. An onshore wind is worse; even a gentle and well-planned landing arc might not keep the vessel from being slammed hard against the wall.

A powerful thruster package is no match for a strong wind. An incredible force develops when just a few dozen tons of vessel are pushed into a face wall at 1 or 2 miles per hour. Now multiply those numbers by 10, and you will see what a challenge it is to overcome this situation.

When cargo ships had sails, wind was essential to commerce. But modern mariners have much less appreciation when the wind blows.

Learn to acknowledge and plan for the wind’s actions on your boat, and your frustration level will go way down. (Well, it will be somewhat better as you make your third attempt at docking.)

Learning to control your boat in not-so-perfect conditions is rewarding and only second to making a perfect landing in a strong crosswind.
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