A deflector (350, 400, 500) configured to be attached to a cable towed by a vessel and configured to connect to a streamer or a source for a marine survey, the deflector comprising: a wing body (410, 420, 510, 520) including a first part (410, 510) joined to a second part (420, 520) to form a swept-back-wing shape, the first part and the second part being substantially coplanar, wherein a first straight line stretching along at least a portion of a front edge (412, 512) of the first part makes a first angle (α 1) with a second straight line stretching along at least a portion of a front edge (422, 522) of the second part, a third straight line stretching along at least a portion of a trailing edge (414, 514) of the first part makes a second angle (α 2) with a fourth straight line stretching along at least a portion of a trailing edge (424, 524) of the second part, the first angle and the second angle being non-zero angles, characterized in that the deflector further comprises a first ballast body located at an end of the first part opposite to the joining axis; and a second ballast body located at an end of the second part opposite to the joining axis, wherein the first ballast body and the second ballast body have a shape configured to have low fluid friction when the body moves substantially parallel to the joining axis, and the first ballast body is lighter than the second ballast body. a wing body (410, 420, 510, 520) including a first part (410, 510) joined to a second part (420, 520) to form a swept-back-wing shape, the first part and the second part being substantially coplanar, wherein a first straight line stretching along at least a portion of a front edge (412, 512) of the first part makes a first angle (α 1) with a second straight line stretching along at least a portion of a front edge (422, 522) of the second part, a third straight line stretching along at least a portion of a trailing edge (414, 514) of the first part makes a second angle (α 2) with a fourth straight line stretching along at least a portion of a trailing edge (424, 524) of the second part, the first angle and the second angle being non-zero angles, characterized in that the deflector further comprises a first straight line stretching along at least a portion of a front edge (412, 512) of the first part makes a first angle (α 1) with a second straight line stretching along at least a portion of a front edge (422, 522) of the second part, a third straight line stretching along at least a portion of a trailing edge (414, 514) of the first part makes a second angle (α 2) with a fourth straight line stretching along at least a portion of a trailing edge (424, 524) of the second part, the first angle and the second angle being non-zero angles, characterized in that the deflector further comprises a first ballast body located at an end of the first part opposite to the joining axis; and a second ballast body located at an end of the second part opposite to the joining axis, wherein the first ballast body and the second ballast body have a shape configured to have low fluid friction when the body moves substantially parallel to the joining axis, and the first ballast body is lighter than the second ballast body. the first ballast body and the second ballast body have a shape configured to have low fluid friction when the body moves substantially parallel to the joining axis, and the first ballast body is lighter than the second ballast body.