A surface-towed sparker designed for use in high-resolution sub-bottom geophysical surveys. It is a catamaran based device with integral buoys offering an adjustable depth capability. It features a high amplitude short duration pulse with minimal reverberation, with sparker tips arranged in a planar horizontal design. Different sparker tips can be used to increase resolution or penetration as required. It has an operating voltage ranging from 3000-4000 v and a power range of 600 J-2400 J, with a maximum energy output of 2500 J.