|
|
|
Feature Articles
Reprinted from Commercial Fisheries News
|
Wind, cold compound fishing dangers
|
This article is reprinted with permission of Commercial Fisheries News, the Northeast's fishing newspaper for over 30 years, ©2003 Compass Publications Inc. Commercial Fisheries News is published monthly; annual subscriptions are $21.95. To subscribe or request a sample issue: call (877) 263-4496; fax (207) 367-2490; e-mail (cfoster@fish-news.com); or click on the hot link.
by Ann Backus, MS
Director of Outreach
Department of Environmental Health
Harvard School of Public Health, Boston MA
Phone (617) 432-3327;
E-mail abackus@hohp.harvard.edu
Bitter cold and windy days at the beginning of December and a serious and unusual winter ice storm in the Carolinas are reminders that we need to talk about icing and wind chill.
This is not a new FISH SAFE topic, but one that bears repeating because icing can present such significant and sudden hazard.
Ice is heavy. If a boat's stability is already compromised by top-heavy fishing gear rigging or by hauling practices that "tow high" and/or by loads of fish not evenly distributed in the holds, accumulating ice on the hull, deck, and rigging can make your vessel vulnerable to capsizing.
Icing occurs when the air temperature falls below freezing and the windspeed is generally in excess of 15 knots per hour.
The colder the surface temperature of the body of water, the faster the icing takes place. In the Northeast, the conditions most likely to produce icing are a wind out of the north or a winter Nor'easter.
To reduce ice build-up on your vessel under these conditions, head for shore or alter course to downwind. When removing ice, start from the highest point and work down, being careful to maintain footing and balance.
The National Weather Service has developed icing models based on sea temperature, windspeed, air temperature, and the freezing point of sea water and has constructed three categories for characterizing freezing spray and icing:
- Light Icing (aqua on charts) - Less than 0.3" per hour;
- Moderate Icing (blue) - 0.3"-0.8" per hour; and
- Heavy Icing (red) - More than 0.8" per hour.
Fishermen can check out these color-coded icing forecasts on the Internet at www.polar.ncep.noaa.gov. Marine forecasts available at www.mpc.ncep.noaa.gov may contain a reference to "light freezing spray" as it did on Dec. 8.
Although icing itself will not trigger the severe weather alert alarm on a weather radio equipped with Specific Area Message Encoding (SAME), the conditions that promote icing include low temperatures and high winds.
Fishermen who receive their weather forecasts by Atlantic Ocean Radio Facsimile may see the open half-circles with the flat side up and one or more lines through them designating the severity of icing.
Two caveats should be mentioned here. First, fishermen who have a Midland 74-200 weather radio manufactured between May 1999 and August 1999 with a serial number beginning with 904 or 905 should check with their supplier or the manufacturer because some of these units have failed to recognize the SAME signal.
The National Weather Service recommends that fishermen test their SAME signal weekly on Wednesdays between 10 am and noon, local time.
Other hazards
Icing causes not only vessel instability, it can also: create a slip-and-fall hazard; obscure running lights; interfere with the proper operation of winches and other machinery; and
"weld" the EPIRB and life raft to the superstructure, preventing their release in a capsize emergency.
Ice on radio antennas and radar can seriously interfere with radio communication and radar signals because it reduces the amount of radio energy that is reflected back, essentially lowering the "radar signature" of a vessel.
Wind chill
Like icing, wind chill is dependent on air temperature and wind speed. Wind chill is a measure of how temperature and windspeed feel to the skin.
For example, at 20° F with a windspeed of 20 knots, the skin feels and behaves as if the temperature is 4°. At 4° F, frostbite occurs in 30 minutes. On weather tables, the abbreviation WCI stands for Wind Chill Index.
Hypothermia is also likely in extreme cold conditions. A person whose body temperature falls below 95° F is considered hypothermic and must be cared for according to specific protocols in order to avoid heart failure.
A wind chill graph, revised in November 2001, and a wind chill brochure are available at www.nws.noaa.gov. Click on the winter picture.
Fish Safe:
- Consult Internet weather forecasts regularly, including http://polar.ncep.noaa.gov, for icing forecasts.
- Avoid fishing in conditions that lead to icing and low wind chill temperatures.
- Remove ice from lights, machinery, rafts, EPIRBs, rigging, antennae, and radar equipment.
- Cover exposed skin and provide guidance to crew about the signs of hypothermia.
|
|
|
|
