The company's principal activity is to provide an integrated range of onshore seismic drilling, permitting, helicopter support and survey services. the services are offered to geophysical companies operating in logistically difficult and environmentally sensitive terrain in the continental united states. the primary market of the company is in the marsh, swamp shallow water and contiguous dry land areas along the united states gulf coast. the company owns and operates an extensive fleet of specialized seismic drilling and transportation equipment for use in the transition zone, much of which is fabricated by the company. drilling accounted for 76% of 2001 revenues; Aviation, 15%; Permitting, 6% and survey services, 3%.