EXHIBIT 21.1 OMNI Energy Services Corp's Subsidiaries OMNI Energy Services Corp Trussco, Inc. Trussco Properties, L.L.C. American Helicopters Inc. OMNI Energy Seismic Services Corp OMNI Offshore Aviation Corp OMNI Seismic Aviation Corp OMNI Properties Corp. OMNI Energy Services Corp. - Mexico OMNI Energia Mexicana OMNI International Energy Services American Aviation L.L.C. OMNI Energy Services - Alaska, Inc. Hamilton Drill Tech, Inc. Gulf Coast Resources, Inc.