Scattering or time‐varying mechanisms in the oceanic medium can affect the performance of a passive broadband cross‐correlation system. These mechanisms include internal waves, sea‐surface motion, and angular spreading caused by rough boundaries. The system involves three horizontal, collinear sensors and source location parameters are determined from time‐delay estimates obtained by cross‐correlation techniques. Tests for measuring the amount of spread or wander in correlograms with sufficiently high signal‐to‐noise ratios are presented. These tests are useful for determining the magnitued of the combination of scattering and time‐varying effects in correlogram data. Spread is measured by comparing the average main‐lobe width of stabilized correlograms over a period of time to the width of an ideal, “frozen‐ocean” correlogram. Wander is estimated by a comparison of the standard deviation of correlogram peak location values over a period of time to the average main‐lobe width of these correlograms. Examples of the application of the tests to simulated data are discussed. Finally, there is an identification of several correlogram types that can be associated with large amounts of spread and wander.