Disclosed are methods and systems for towing one or more electromagnetic sensor streamers from deflectors in an additional geophysical sensor streamer spread. An embodiment discloses a marine geophysical survey system, comprising: a survey vessel; an electromagnetic sensor streamer; and a geophysical sensor streamer spread configured to be towed by the survey vessel, wherein the geophysical sensor streamer spread comprises: sensor streamers configured to be laterally spaced apart from one another; and deflectors adapted to spread the sensor streamers substantially transversely in relation to a direction of motion of the survey vessel, wherein the electromagnetic sensor streamer is configured to be towed from at least one of the deflectors.