Put on your personal flotation device and prepare for rough seas. Stay below deck if possible. Keep away from metal objects that are not grounded to the boat's protection system. Don't touch more than one grounded object at the same time. A severe thunderstorm watch means that conditions are favorable for development of thunderstorms capable of large hail and damaging winds.
ALL thunderstorms produce deadly lightning.
Watch the sky and monitor NOAA Weather Radio and commercial radio and television stations to know when warnings are issued. A basement or first floor interior room is best. Severe thunderstorms can spawn tornadoes with little or no warning. Get your car under safe cover if possible. A severe thunderstorm warning means that thunderstorms capable of producing large damaging hail and strong damaging winds have been reported or are indicated by Doppler radar.