Yes, very dangerous.
Waterspouts are tornadoes that form closer to the surface of the water than do most land-based tornadoes. They are usually associated with severe thunderstorms near bodies of water, but they can also happen away from obvious weather systems. Waterspouts move over the surface of a body of water at a relatively slow speed and still take out anything in their path - even other types of force like rainfall and breezes (because it's not rain and breezes). Although dangerous, waterspouts will usually dissipate quickly or downgrade into a smaller fluffy cumulus cloud after hitting the ground or running out shoreline.