To examine water around a peptide or protein site with COOR ANAL, I think you want to use the SITE keyword, and omit the WATER keyword, as in the 3rd g(r) example for water O around backbone HN in corman.doc

If the site is somewhat buried, you may wish to consider exploring the excluded volume options.

COOR HBOND might also be useful to compute how often the site is occupied, and the average lifetime of H-bonds.