  A Costas latin square of order n is a set of n disjoint Costas arrays of the
same order. Costas latin squares are studied here from a construction as well
as a classification point of view. A complete classification is carried out up
to order 27. In this range, we verify the conjecture that there is no Costas
latin square for any odd order n >= 3. Various other related combinatorial
structures are also considered, including near Costas latin squares (which are
certain packings of near Costas arrays) and Vatican Costas squares.
