These waves travel at the speed of sound, but when a jet travels at Mach 1 and above these waves merge into one single shock wave as they cannot get out of the way of each other quickly enough.

CNN: Bang goes the sonic boom

The morning haze had burned off, and in the noon light the brackish water appeared deceptively lovely, its surface undisturbed except for a single Jet Ski carving a white wake whose exhausted wavelets lapped at the riprap at the side of the road.

NPR: In 'Challenger Park,' Mom Is an Astronaut