A method and system for deploying seismic tows, such as seismic streamers, from a common carrier rope for conducting marine seismic surveys. The deployment system generally comprises a carrier rope having at least one deflector urging the carrier rope laterally relative to the towing vessel and seismic tows that are independently moveable along the deployed carrier rope to desired locations from which to be deployed. The carrier rope may be deployed from the tow vessel into the water prior to deploying the seismic streamer(s) into the water.