Even a relatively mild blow can be a knee-wobbler, especially if you're on a smaller boat or out with your family. You don't have to be a trained meteorologist to spot bad weather on the approach, you just have to refresh yourself with the basics of storm-spotting, and remember, the more indicators of bad weather you see, the more important it is to head for port immediately. Better to be safe than sorry. 

Observe The Clouds  
As a general rule, gathering clouds indicate a gathering storm, so always keep your eyes on the skies. A laminated cloud chart (available from www.cloudchart.com) is a pretty cool thing to keep on board, as it helps you identify cloud formations quickly and positively. Even without a chart, you can easily spot potential bad weather by watching for sudden changes in the clouds or their formations. Two developments are particularly important to watch for. A "lowering ceiling," in which the clouds and their height seem to be getting lower and lower, is usually caused by an approaching warm front. Second, and more dramatic, is when puffy cumulus clouds begin to grow vertically (get taller), indicating an imminent thunderstorm. Also, remember that in the United States, most weather systems move from west to east, so keep an extra-sharp eye out to the western horizon for approaching trouble. 

Feel The Wind
When you're out on the water on a hot summer day, a cool breeze is sweet. But if you notice the temperature suddenly dropping more than a couple of degrees, especially if the winds are picking up or changing direction, that's a sure sign it's time to head for home. Cold fronts are notorious for bringing squalls and thunderstorms, and an approaching front will frequently show itself first by increased winds actually blowing toward the approaching front, as the low pressure associated with the front draws air. When the front arrives, you'll usually notice that the winds suddenly shift 180 degrees, and instead of being refreshingly cool, the breeze can be downright chilly. If you notice that it's suddenly gotten quite a bit cooler on board, especially if it's gotten windier as well, look quickly to the skies for signs of storms and make your way to port.

Watch The Pressure
Mariners and meteorologists know that low-pressure systems have a strong tendency to generate intense, dangerous storms. Thunderstorms, tornadoes and hurricanes tend to cluster around low-pressure systems, giving boaters at least three good reasons to get off the water if and when the atmospheric pressure starts dropping. The tough part is, we can't tell by sight, sound, or touch when the pressure drops. That's why the smart boater keeps a barometer on board. Mount the barometer on the dash at the helm and check it every two or three hours. Make sure your barometer has a "set needle" that you can use to mark the pressure when you arrive on the water - this way, you can see changes in atmospheric pressure at a glance and take appropriate action.

Tune In
The ultimate weather warning system is one that should be on every boat and in every home - an NOAA Weather Radio. Depending on its features, these radios cost anywhere from $20 to over $200. You can save money by getting a basic, battery-powered unit, making sure that it carries the "Public Alert" logo, indicating that the unit meets the Public Alert Standard set by the Consumer Electronics Association and the National Weather Service. When dangerous weather approaches, NOAA broadcasts a 1,050-hertz tone that will automatically turn on the radio so you can be sure you'll receive the warning, even if you're catching 40 winks on a summer afternoon. Replace the batteries every six months, and the NOAA Weather Radio will be your last, best line of alert when there's a chance the weather could go sour.