Saturday, June 20, 2009

Weather for the Small Boat Operator

Tune a portable radio to a local station that gives weather updates. Listed below are the VHF-FM radio stations that broadcast National Oceanic and Atmospheric Administration (NOAA) weather reports, which are updated each hour.

Be alert to weather conditions. Accumulating dark clouds, shifting winds, and graying skies all may be indications of danger. Track changes in barometer readings. A rising barometer indicates fair weather. A falling barometer indicates foul weather is approaching. Watch for wind direction shifts, which usually indicate a weather change. Watch for lightning and rough water. If not electrically grounded, boats (particularly sailboats) are vulnerable to lightning.

Be observant of weather from all directions, watch the weather to the west, the direction from which most bad weather arrives. Watch for fog that creates problems in inlets and bays. Typically, fog will form during the temperature changes of the early morning or evening hours and can persist for lengthy periods. Head toward the nearest safe shore if a thunderstorm is approaching.

Prepare your boat for bad weather:
Slow down, but keep enough power to maintain headway and steering.

Close all hatches, windows, and doors to reduce the chance of swamping.

Stow any unnecessary gear.

Turn on your boat's navigation lights. If there is fog, sound your fog signal.

Keep bilges free of water. Be prepared to remove water by bailing.

If there is lightning, disconnect all electrical equipment. Stay as clear of metal objects as possible.

Prepare your passengers for severe weather:
Have everyone put on a USCG approved life jacket (PFD). If a PFD is already on, make sure it is secured properly.

Have your passengers sit on the vessel floor close to the centerline. This is for their safety and to make the boat more stable.

Decide whether to go to shore or ride out the storm.
If possible, head for the nearest shore that is safe to approach. If already caught in a storm, it may be best to ride it out in open water rather than try to approach the shore in heavy wind and waves.

Head the bow into the waves at a 45-degree angle. PWCs should head directly into the waves.

Keep a sharp lookout for other vessels, debris, shoals, or stumps.

If the engine stops, drop a "sea anchor" on a line off the bow to keep the bow headed into the wind and reduce drifting while you ride out the storm. In an emergency, a bucket will work as a sea anchor. Without power, a powerboat usually will turn its stern to the waves and could be swamped more easily. If the sea anchor is not sufficient, anchor using your conventional anchor to prevent your boat from drifting into dangerous areas.
To determine the distance you are from an approaching thunderstorm:
Count the number of seconds between the flash of lightning and the clap of thunder.

Divide the number of seconds by five. The result is roughly the distance in miles you are from the storm.

VHF-FM Stations for NOAA Weather Reports. NOAA Weather Radio broadcasts weather forecasts and warnings using these frequencies:
162.400 MHz

162.425 MHz

162.450 MHz

162.475 MHz

162.500 MHz

162.525 MHz

162.550 MHz

Weather Warning Display Signals
Daytime Flags & Nighttime Lights: What the Signals Mean:

Small Craft Advisory: Winds in the range of 21 to 33 knots (24 to 38 mph) create conditions considered dangerous to small vessels.

Gale Warning:Winds are in the range of 34 to 47 knots (39 to 54 mph).

Storm Warning:Winds are 48 knots (55 mph) and above. If winds are associated with a tropical cyclone, this warning signals winds of 48 to 63 knots.

Hurricane Warning:Winds are 64 knots (74 mph) and above. This warning is displayed only in connection with a hurricane.