You would need to account for drag and windage. Basically know everyone's hull shape and CFD it! And the seabed under them. At a distance it's easy - but in co

You would need to account for drag and windage. Basically know everyone's hull shape and CFD it! And the seabed under them. At a distance it's easy - but in confined waters it gets very complicated very quickly. I've seen situations where literally the only solution is, who do I collide with. In the case of the USN they have a hell of a lot more manoeuvrability than a freighter but they can't escape the laws o'physics...