Boats passing over smooth water form a pair of diffusion wakes behind them veering off at a certain angle. Turbulence occurs along the line directly behind the boat, but the two diffusion waves are at a theoretical angle of 19. 5° from the same line, for deep, ideally smooth water.
Source: [Phys.org](https://phys.org/news/2026-09-years-jet-diffusion-quark-gluon.html)