Atmosphere And Weather

Guidelines for Avoiding Hurricanes at Sea



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"Guidelines for Avoiding Hurricanes at Sea"
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On land, people in hurricane-prone areas pay close attention to the track of incoming hurricanes. The same is true when avoiding hurricanes at sea. Information is by far your best tool to avoid a hurricane at sea: and your radio is your lifeline.

To avoid a hurricane at sea, you first have to know your current location. The new-fashioned way of doing this is by GPS, with hurricane locations given the same way.

It used to be much more difficult. Before GPS became the norm, location could be determined through radio triangulation or, for the really old-fashioned way, by dead reckoning. The results derived by these methods then had to be charted against the coordinates of the hurricane.

Now that you know your exact location and the hurricane's current location and estimated track, it is time to follow a few simple rules.

34 KT rule:
Stay clear of the wind field of a hurricane, right up to the 34 knot limit. Beyond this point, sea conditions worsen quickly: and you may not be able to adjust course and speed in time to avoid being swept deeper into the hurricane. Allow even more space if there is any hint of explosive growth in size or intensity.

1-2-3 rule:
This rule establishes the minimum recommended distance from a hurricane, based on how much in advance the forecast is. For a 24 hour forecast, allow at least 100 miles error radius from the 34 knot wind field. For a 48 hour forecast, allow 200 miles; and for a 72 hour forecast, allow 300 miles. Increase this distance further if you need to allow for greater forecast uncertainty, limited crew experience, decreased vessel handling, or any other complicating factor.

Never Cross The "T" rule:
Never plot a course that will take you across the forecast track of a hurricane. The speed and direction of a hurricane can change without warning.

Closest Point of Approach rule:
Compare CPA against your current and future possible evasion options. Your CPA should always be increasing. Any decrease in CPA is a matter of utmost urgency: and requires fast reevaluation of your current course and options.

Multiple Options rule
Never leave yourself only one option if you can possibly help it. Avoid restricted manoeuvre areas when there are incoming storms.

Take into account the port's facilities before deciding whether to avoid the hurricane or head to port to ride it out. You may want to give a pass to a port likely to be in the hurricane's right front quadrant during landfall: where hurricanes are at their most intense.

In addition to following these rules religiously, update available hurricane information and compare it against your course as often as updates are available. Also compare the current forecast track of the hurricane with previous forecast tracks. You may be able to spot a pattern: and thereby gain early warning of the hurricane's likely future behaviour. Allow space in those directions as well, even if they are not included in the current forecast path.

Where hurricanes are concerned, don't ever rely solely on advance forecasts. The margin of error for intensity and track is simply too high.

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