The following is a safe boating message from the National Safe Boating Council and the National Weather Service.
Understanding a marine forecast is critical to safe boating. Weather and wave conditions can change suddenly, catching boaters off guard and creating life threatening conditions.
Typical marine forecasts predict wind speed and direction, wave heights and periods, roughness of near shore waters, and significant weather. Marine forecasts cover large areas and the forecast elements are often given in ranges. The significant weather may not occur over the entire area or during the entire forecast period. The ranges represent average conditions over a period of time (usually 12 hours) and the actual conditions may be lower or higher than the forecast range. Boaters should plan for conditions above and below the predicted ranges.
Take particular note of any current advisories and warnings, including Small Craft Advisories, Gale or Storm Warnings which alert mariners to either high winds or waves occurring now or forecast to occur up to 24 hours from now. Special Marine Warnings are issued for sudden increase in winds to over 35 knots (40 mph), waterspouts (tornadoes over water), and hail of ¾ inches or greater and indicate a more immediate threat. Marine weather statements bring attention to significant rapidly changing conditions on the water including increase in winds, non severe thunderstorms, development of dense fog and even snow squalls or strong and gusty rain showers.
You should have a marine VHF transceiver with built-in NOAA Weather Radio channels. If you venture beyond about a 25 nautical mile range from shore, you should consider buying a good quality HF single sideband transceiver and satellite phone.
Before setting out, obtain the latest marine forecast and warning information from www.weather.gov/marine or NOAA Weather Radio. Several days ahead of time you can begin listening for extended outlooks which give general information out to the next five days in both graphical and text format.
This message was brought to you by the National Weather Service and the National Safe Boating Council. Visit the National Weather Service on the web at www.weather.gov and the National Safe Boating Council at www.safeboatingcouncil.org
www.weather.gov 
