[SeaQueen]

You asked a deeper question than you realize...

The Orion Warriors manual has some good stuff in it. There's a few points I dislike, though. I think in the interest of simplicity they described a datum search, but that's not the best way to do it. If the time late is so small then one probably ought to just drop a DICASS on the thing, ping and find it. Either that, or do a non-acoustic search with the MAD. A datum with almost no time late means you've already localized him and you don't need to do much besides drop a torpedo. More typically a datum procecution has some appreciable time late associated with it. By making different assumptions about the target's motion based on what one already knows, one can work out the distribution of possible submarine locations as a function of time late. The simplest assumption is to assume that all courses are equally likely and the sub will continue at constant speed. If that's the case the target's location distribution looks like a circle and the best possible search is one which spirals outwards. There's a table in the Ow manual that has something to do with that, but they never make any diagrams or emphasize it.