Abstract: Techniques are disclosed relating to geophysical surveying. In some embodiments, a marine survey vessel tows multiple sensor streamers including a group of four innermost streamers in a cross-line direction relative to a centerline of tow. In some embodiments, the vessel tows two or more vibratory sources between two outermost streamers in the first group, in a cross-line direction. In some embodiments, the two or more sources are simultaneously operated using different codes that are uncorrelated to at least a threshold degree. Various disclosed narrow-tow techniques may allow increased streamer separation without reducing cross-line bin size and/or reduce cross-line bin size for a given streamer separation, relative to conventional techniques.