NESTOR is a deep-sea neutrino telescope that is under construction in
the Ionian Sea off the coast of Greece at a depth of about 4000 m. This
paper briefly reviews the detector structure and deployment techniques
before describing in detail the calibration and engineering run of a
test detector carried out in 2003. The detector was operated for more
than I month and data was continuously transmitted to shore via an
electro-optical cable laid on the sea floor. The performance of the
detector is discussed and analysis of the data obtained shows that the
measured cosmic ray muon flux is in good agreement with previous
measurements and with phenomenological cosmic ray models. (c) 2005
Published by Elsevier B.V
