A weak bore of height Δ on water of depth h, seen from a frame moving at c₀ = √(gh) (Korteweg and de Vries, 1895). With η = Δu, X = a x and t = b τ, where a = h√(2h/3Δ) and b = 6a³/(c₀h²), every such bore is the same solution of uτ + 6uux + uxxx = 0 from a step of 1 to 0. That solution is computed once, on a fine grid, and the page only stretches it: the depth and the height change the scales, never the shape.
Published (Gurevich and Pitaevskii, 1974): the train fills −6 < x/τ < 4, its first wave tends to twice the step, and new waves are born at 2.55 per unit of τ. Published (Rayleigh, 1914): a bore that breaks burns ρgc₀Δ³/4h per metre of width. Ours: the grid, the bore that breaks (the same equation with a viscous term), and every number on this page. Favre's flume experiments (1935) found bores breaking above about 0.28 of the depth, where this slider stops.