The River of Space Substrate flows radially inward toward a central mass, speeding up as v_ebb(r) equals the square root of 2GM over r — slow blue arrows far out, fast red arrows near the centre. Where the inflow reaches the speed of light it crosses the horizon at r_s = 2GM/c squared. Substituting this self-consistent flow into the Unruh-Visser acoustic metric yields the exact Painleve-Gullstrand form of the Schwarzschild solution, from which gravitational redshift, light deflection, Shapiro delay, and perihelion precession all follow exactly. The River of Space Space itself flows inward at vebb = √(2GM/r). Feed that flow into the acoustic metric and you get the Schwarzschild solution — exactly, not approximately. M horizon: vebb = c rs = 2GM/c² inflow speed grows toward M far / slow faster v → c From flow to spacetime the self-consistent steady inflow… vebb(r) = √(2GM / r) vebb dvebb/dr = −GM/r²  from substrate Euler + continuity …dropped into the acoustic metric… ds² = −(c² − vebb2) dt² − 2vebb dr dt + dr² + r² dΩ² = Painlevé–Gullstrand Schwarzschild exact — not linearized, not approximate where vebb = c the river outruns sound: an acoustic horizon, rs = 2GM/c² every static GR test follows exactly redshift · light-bending · Shapiro delay · perihelion precession · GPS