High winds that can blow equipment off the deck and cause persons on board to lose balance and fall overboard. Boats caught out on open water under these conditions can encounter a downburst without expecting it. This fact makes predicting their occurrence almost an impossible task. Witnesses claim in less than two minutes, the ship was blown over, filled with water, and sank. Although this tragedy involved a larger sailing vessel on the open ocean, similar dangers have been experienced by vessels on inland or inshore waters.
Thunderstorms can create several downbursts in succession, with varying degrees of intensity.
A thunderstorm might even generate a combination of downbursts and tornadoes. The best source of current weather information is the continuous National Weather Service broadcasts. Seven frequencies between 162.400 and 162.550 MHz have been set aside for this purpose. Taped information is recycled approximately every five minutes with broadcasts updated no less than every three to six hours. In the event of unusual or severe weather, the programming may be interrupted by live broadcasts.