Small underwater objects such as vehicles and divers can pose threats to fixed installations and ships. For ships, these threats are present both at sea and in harbors. Shallow underwater targets, including drifting mines, are difficult to detect with acoustic methods and thus complementary methods are required. If an airborne platform is available, some of those targets could be detected by passive optical means. However, for sensing from a ship or from land, optical detection can be highly improved by use of a pulsed laser system. We present simulated data of importance for the design of a lidar system with low incidence angle with respect to the water surface. We also present our first experimental data from underwater target detection with an incidence angle of 5 degrees.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.