A method and apparatus steers the returning beams of a receiver in a swath bathymetric system to an actual target based on prior steering angle information for the target and using an algorithm which demonstrates a linear relationship between the phase of the return beam and the steering angle therefor. The receiver comprises a plurality of transducing elements which each emit a signal. The array is divided into two groups of elements which are processed and combined to form beams for each group which are steered to the known steering angle for the target. Beams are then steered to a slightly offset angle to produce an offset beam. Using an equation to define each return beam according to phase and error between prior known and actual steering angles for the target, the error value can be reduced to zero to provide an accurate measurement of the actual steering angle for the target.