Sailing: What You Need To Know
March 18, 2009
By WeatherBug Meteorologist, Angela Johnson
Sailing and boating is one of the great American leisure activities, but staying safe means keeping track of the weather.
The U.S. Coast Guard (USCG), National Weather Service and local authorities offer important marine weather products that all boaters should be aware of before and during their trips on America`s rivers, bays, lakes, gulfs and oceans.
Here is a list of the important, widely available products for both seasoned mariners and casual boaters alike:
High frequency signals, which bounce off the ionosphere high above the earth, are great ways to transmit data and voice across long distances.
The USCG Communications Centers are located in Boston, New Orleans, Kodiak, Alaska, Pt. Reyes, Calif., and Honolulu. The main products transmitted include upper-air 500 millibar (mb) charts, surface pressure, and sea state charts along with sea surface temperatures (SST), tropical streamline and surface analyses, and satellite imagery. Each Communications Center puts out a broadcast about every 6 hours to users equipped with special marine fax equipment.
These radiofax help sailors and mariners prepare and avoid open sea hazards like hurricanes, thunderstorms, extreme wind and rain storms and high waves.
A very high frequency wave, which is affected little by solar activity, has a typical coverage of about 20 nautical miles offshore. The USCG broadcasts coastal water forecast and marine warning produced by local National Weather Service forecast offices. This network provides near continuous coverage of coastal U.S., Great Lakes, Hawaii, populated Alaska coastline, Puerto Rico, the Virgin Islands, and Guam. Marine VHF radio, available at most marine stores for less than $130.00, should be on all vessels in order to get latest, up-to-date near-coast forecast and warnings.
A medium frequency (MF) transmission follows the curvature of the earth all the time and reflects off the ionosphere at night. This makes for a daytime range of 50-150 nautical miles and a nighttime range of 150-300 nautical miles. USCG broadcasts National Weather Service offshore forecasts and storm warnings prepared by the Ocean Prediction Center, Tropical Prediction Center, Anchorage Forecast Office and Honolulu Forecast Office. A non-directional beacon aboard is needed in order to hear the forecasts and warnings put out on the medium frequency.
High frequency voice, which reflects off the ionosphere very well can vary from a short distances to several thousand miles. The USCG broadcasts high-seas forecasts and storm warnings prepared by the Ocean Prediction Center, Tropical Prediction Center and Honolulu Forecast Office. In order to receiver this important weather information a Single Sideband (SSB) radio and antenna is needed and all vessels should carry one.
NOAA weather radio
The NOAA weather radio provides voice broadcasts of coastal and marine forecasts continuously. This network covers almost all of the continental United States, Hawaii, populated Alaskan coastline, Puerto Rico, the Virgin Islands, Guam and the Northern Mariana Islands. When there is a severe weather threat, an alarm tone is sent to the radios in the transmitter`s coverage area, which usually extends about 25 nautical miles offshore. NOAA also offers recorded marine forecasts by telephone.
The Internet is also another place to find information on marine weather. Marine websites include: NOAA`s home page: http://www.noaa.gov, Marine and Coastal Weather Services Home page: http://www.nws.noaa.gov/om/marine/home.htm, NOAA`s National Ocean Service home page: http://www.nos.noaa.gov, USCG home page: http://www.uscg.mil and the USCG Navigation center: http://www.navcen.uscg.gov/marcomms/.
Another option before heading out or while out on the water is Dial-A-Buoy. By dialing (888) 701-8992 you can get wind and wave measurements taken within the last hour. When dialing into the system, use the five-digit station/buoy identifier to receive the latest information. If you are not sure of the buoy number, information can be found at http://seaboard.ndbc.nooo.gov/dail.shtml.
Before heading out on the water, all mariners should know what weather to expect and have the equipment to get updates.
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