Abstract: A method of determining depth values for the bottom profile of a body of water from pulse transit times and sounding directions by means of a fan beam echo sounder that measures transversely to the longitudinal axis of the ship, whose transducer array is installed at an angle obliquely to the vertical elevation axis of the ship and wherein the pulse transit times are measured and stored in association with the sounding directions, with the sounding directions .alpha..sub.oi being calculated from data furnished by the transducer array and by the transducer signals as well as by means of a predeterminable sound velocity c.sub.o at the surface of the transducer array. For each transducer array, selected depth values are determined in the vertical sounding direction .alpha..sub.ov and in a sounding direction .alpha..sub.On that is normal to the plane of the transducer array. Estimated depth values for an estimated profile are determined for all remaining sounding directions .alpha..sub.