Illustration of nonlinear loss in the sound beam, using the numerical results for 200 kHz, 1000 W. Left: Two-way intensity beam pattern at 14 m range, with and without correction for nonlinear loss in the forward propagating wave. Centre: Two-way intensity beam pattern at 14 m range, corrected for nonlinear loss upon both measurement and calibration at the same range. Right: Two-way intensity beam pattern at r = 300 m range, corrected for nonlinear loss upon measurement and upon calibration at r_cal = 14 m range.