  This paper is a brief review of the status of the search for astrophysical
neutrinos of high energy. Its emphasis is on the search for a hard spectrum of
neutrinos from the whole Northern sky above the steeply falling background of
atmospheric neutrinos. Current limits are so low that they are beginning to
constrain models of the origin of extragalactic cosmic rays. Systematic effects
stemming from incomplete knowledge of the background of atmospheric neutrinos
are discussed.
