The quest for the ideal photodetector for the next generation   deep-underwater neutrino telescopes
  We review photodetectors used in present running neutrino telescopes. After a brief historical discourse, the photodetector requirements for the next generation deep underwater neutrino telescopes are discussed. It is shown that large area vacuum hybrid phototubes are the closest to the ideal photodetector for such kind of applications when compared with other vacuum phototubes. 
B.K.Lubsandorzhiev