Lightning, torrential rain and rough seas can turn a pleasurable outing into a life-threatening ordeal in a heartbeat. Yet unwary boaters are too often taken by surprise, largely because they don’t realize just how fast a storm can come up or the danger it presents.
According to the most recent Coast Guard accident data, nearly three percent of all recreational boating accidents are directly related to severe weather conditions that can quickly overwhelm smaller craft. Some thunderstorms, for example, create microbursts – intense downdrafts over an area a half-mile to three miles wide capable of producing wind gusts from 60 mph to more than 100 mph. Microbursts can capsize a small boat or blow a passenger overboard.
No one wants to end up a statistic. The risks of swamping, capsizing, falling overboard or hitting a floating object all increase in stormy weather, so out on the water the most important equipment on board is always a Coast Guard-approved life jacket for all passengers. And plan to err on the side of caution. Careful attention to marine weather forecasts and staying alert to sudden changes can help keep both good times and safety at a maximum.
Most boaters already know to track the extended five-day forecast, either on local AM/FM radio or television, or on Internet weather sites like the National Oceanographic and Atmospheric Administration’s (NOAA) Marine Forecast and information web page at www.weather.gov/om/marine/home.htm. At marinas, small craft advisories, storm warnings, and other alerts warn boaters of higher wind and waves, either imminent or expected within the next 24 hours.
Once on the water, technology has given operators of even very small boats an edge. VHF-FM weather radios or VHF transceivers with built-in NOAA weather radio channels are readily available at most retail outlets, with HF single sideband transceivers as a backup for those ranging farther out on the water.
Monitoring the latest weather reports can warn boaters if conditions are right for severe weather. But knowing there’s a chance of a thunderstorm won’t tell you when one is headed your way.
For larger recreational boats, a barometer is a valuable tool to have on board, and to check every two to three hours. A rise in barometric pressure signals fair weather. A rapid drop means a fast approaching storm.
Weather fronts typically move in from the west/southwest, so scanning the horizon in that direction periodically can pick up far off lightning flashes and other signs (See sidebar).
Being able to recognize storm cloud patterns is also a useful skill. A “lowering ceiling” -- flat clouds getting lower and thicker – means an approaching storm front. A hot, humid day frequently means thunderstorms as radiant heat from the land picks up moisture from the water and puffy, vertical clouds grow into thunderheads. Result: a violent squall, accompanied by a sudden drop in temperature, sharp winds, suddenly heavier seas, and an increased risk of those micro-bursts we talked about.