A method of assisting navigation of a vehicle, the method comprising the steps of: at predetermined instants, determining first positions and second positions of the vehicle by different positioning means and calculating the discrepancy between each pair of first and second positions; comparing the discrepancy with a warning threshold; defining a reference frame on a screen, the reference frame being centered on a reference point corresponding to the most recent first position; and symbolizing the discrepancies on the screen by allocating a symbol to each discrepancy and by positioning each symbol on the screen, relative to the reference point, while taking account both of the value of the discrepancy and also of the path travelled by the vehicle since calculating the discrepancy, the first symbols being provided with respective chronological indicators.