Airborne laser depth sounding is a promising technique for rapid and high -density sounding of shallow waters. Depth accuracy analysis for laser depth sounding has almost exclusively dealt with horizontal flat bottoms. The objective of this work is to simulate and compare the influence of different shapes of small objects placed on the sea bottom. For this purpose an analytical mode] approach is used to characterize the signals received from objects of size 1 m3 on bottom depths between 5 m and 12 m. Two object types are compared: a cylinder and a cube. The difference in the signal received is small between these objects. Simulated data are compared with experimental data and show good agreement. The probability of small shoal detection critically depends on the horizontal position of the shoal in the laser beam and the shoal height above the bottom. From comparisons between a large number of simulations and measurements the performance is discussed in terms of covered area for one laser shot enabling detection of the shoal.