Coded signals for marine vibrators

Embodiments may be directed to marine vibrators and associated methods that use appropriately selected composite code sequences. A method of seismic surveying may comprise operating a plurality of marine vibrators. At least one of the marine vibrators may repeatedly cycle through a plurality of composite code sequences that are unique to the at least one of the marine vibrators, wherein two or more of the marine vibrators operate contemporaneously for at least one output interval. The method may further comprise detecting seismic energy with one or more seismic sensors after the seismic energy has interacted with subsurface formations, wherein the seismic energy was emitted from the marine vibrators, wherein the detecting occurs while operating the plurality of marine vibrators. 6 _