It is proposed a method for steering a seismic vessel associated with a sail line and a preplot line. The seismic vessel tows at least one acoustic linear antenna including receivers, the receivers receiving signals generated by at least one source and reflected by subsurface's layers at reflexion points. The method includes: computing, according to a regression method, a shifted preplot line which has a shape substantially identical to the shape of the preplot line and which is the best fit line associated with at least some of the reflexion points; computing a distance D between the preplot line and the shifted preplot line; and providing steering information comprising or based on the distance D to a navigation system or to an operator of a navigation system, to alter the course of the seismic vessel.