Severe marine weather can spell trouble for boaters - especially waterspouts, which are simply tornadoes over water. They are commonly found in tropical areas where thunderstorms are frequent, but they can form in any body of water. USA Today reports "Places around the Gulf of Mexico along with the Atlantic Coast northward to Chesapeake Bay are also likely to see waterspouts. Waterspouts have been reported on the West Coast from Tatoosh Island, Washington, south to San Diego... waterspouts also skip across the Great Lakes and Utah's Great Salt Lake from time to time." By far, the Florida Keys experience the most frequent waterspouts, and Tampa Bay leads the way in the most damage from waterspouts.
There are two types of waterspouts: nontornadic and tornadic. Nontornadic waterspouts, the most common type, are also called fair-weather waterspouts because they are not associated with supercell thunderstorms. They occur in coastal waters and develop in association with dark, flat-bottomed cumulus towers. Tornadic waterspouts form nearly identical to land-based tornadoes, and are more rare than nontornadic.
Waterspouts are unpredictable, but a few signs to watch for as one forms are dark spots on the water, sudden shifts and increases in the wind, and funnels coming from overhead clouds. When a waterspout has fully formed, boaters will see a funnel that extends from the clouds to the water, with small waves surrounding the waterspouts, leaving a wake as it moves across the ocean.
Waterspouts are destructive and present danger to boaters, so before you go boating, know what to do if you see a waterspout.