A computer algorithm is described that automates the processing of refraction data acquired by conventional, multichannel, seismic reflection profiling, beginning with the determination of the first arrival times and ending with a contoured velocity-depth section. Traces for several closely spaced shots are first summed to suppress noise. Each stacked trace is convolved with a box operator to convert the first break to a peak that can be detected by the computer. The algorithm calculates intercept times using running averages of slopes. Depths to refractors are plotted and a velocity-depth profile, interpolated at constant velocity intervals, is printed as a contoured cross-section. A profile crossing Georges Bank, northwest Atlantic Ocean, is interpreted by both automatic and manual techniques for comparison.