A waterspout is a rotating column of air and water mist that forms over a body of water, resembling a tornado but occurring over the sea or a lake. The answer to whether these phenomena can be deadly is a definitive yes, though fatal encounters are uncommon. They pose a genuine threat to marine vessels and individuals on the water, necessitating a clear understanding of their mechanics and associated risks.
Defining Waterspouts and Their Categories
Waterspouts are categorized into two primary types: fair-weather waterspouts and the more dangerous tornadic waterspouts.
Fair-weather waterspouts are the most frequently observed type, forming on the water surface and working their way upward under the base of cumulus clouds. They are generally not associated with severe thunderstorms, instead developing in relatively calm conditions where warm, moist air meets cooler air above. These varieties are typically less intense, often having wind speeds of 50 miles per hour or less, which limits their destructive potential. They tend to move slowly and are usually short-lived, dissipating quickly, especially if they move onto land.
Tornadic waterspouts are the more hazardous category, as they are essentially tornadoes that have either formed over water from a severe thunderstorm or have moved from land onto a body of water. They are accompanied by the same conditions as land-based tornadoes, including high winds, large hail, and lightning. Because they form from the rotation within a mature severe thunderstorm, they develop downward from the cloud base. The wind speeds within a tornadic waterspout can easily exceed 100 miles per hour, making them capable of considerable destruction.
How Waterspouts Cause Injury and Death
The primary mechanisms by which waterspouts cause injury and death are through impact, vessel destruction, and subsequent drowning. The high wind speeds, particularly in tornadic waterspouts, can transform ordinary marine debris into lethal projectiles. Loose objects on a boat, such as equipment, wood, or boat parts, can be lifted and hurled at high velocity, causing blunt force trauma.
A waterspout’s powerful rotation poses a significant danger to any vessel in its path by causing rapid vessel damage or capsizing. Even fair-weather spouts generate enough force to flip small boats and sailboats, and tornadic varieties can generate winds strong enough to lift larger boats out of the water. The sudden capsizing or destruction of a vessel can result in personnel being thrown overboard or trapped beneath the wreckage.
Drowning is the ultimate cause of death in most fatal waterspout incidents, resulting from being submerged after vessel destruction or impact. If an individual is in the water near the vortex, the turbulent surface conditions and the rapid swirling of air and water can make it nearly impossible to breathe.
The destructive power of a tornadic waterspout is measured using the same Enhanced Fujita (EF) scale as land tornadoes, sometimes reaching EF2 intensity, which is more than enough to cause structural failure and severe injury.
Essential Safety Protocols
The most effective safety protocol is to maintain a significant distance from any observed waterspout. Mariners should monitor weather alerts, particularly Special Marine Warnings issued by the National Weather Service, which indicate that waterspouts have been sighted or are expected.
Upon sighting a waterspout, the immediate action for marine operators is to change course and travel at a 90-degree angle to the spout’s apparent trajectory. Attempting to outrun the spout along its path is ineffective, as they can move faster than most vessels. It is imperative to never approach a waterspout to investigate, even if it appears to be a smaller, fair-weather type.
If a collision with the vortex is unavoidable, individuals on a boat should immediately put on life jackets and seek a secure, low area of the vessel. Lowering all sails and securely closing hatches can help minimize damage and prevent water from flooding the boat. Protecting the head and body from potential flying debris is a measure when strong winds are impacting a vessel.