Thank you, never heard of this. It sounds terrifying. > Sneaker waves appear suddenly on a coastline and without warning; generally, it is not obvious that the

Thank you, never heard of this. It sounds terrifying. > Sneaker waves appear suddenly on a coastline and without warning; generally, it is not obvious that they are larger than other waves until they break and suddenly surge up a beach. A sneaker wave can occur following a period of 10 to 20 minutes of gentle, lapping waves. Upon arriving, a sneaker wave can surge more than 150 feet (50 m) beyond the foam line, rushing up a beach with great force. > The force of a sneaker wave's surge and the large volume of water rushing far up a beach is enough to suddenly submerge people thigh- or waist-deep, knock them off their feet, and drag them into the ocean https://en.wikipedia.org/wiki/Sneaker_wave https://en.wikipedia.org/wiki/Sneaker_wave