1. A method for processing an overhead image of a vessel, said vessel having a length, a width and length-to-width ratio, said method comprising the steps of: A) assigning a initial classification and an initial classification probability to said vessel based on said length and said ratio; B) extracting mutually exclusive deck features from said image; C) weighting said initial classification probability using the result of said step B); and, D) combining the results of said step A) and said step C) using a predetermined formula to yield a posterior classification probability for said ship.