  We investigate the potential of using massive clusters as gravitational
telescopes for searches and studies of supernovae of Type Ia and Type II in
optical and near-infrared bands at central wavelengths in the interval 0.8-1.25
microns. Using high-redshift supernova rates derived from the measured star
formation rate, we find the most interesting effects for the detection of
core-collapse SNe in searches at limiting magnitudes m_lim~25-26.5 mag, where
the total detection rate could be significantly enhanced and the number of
detectable events is considerable even in a small field. For shallower
searches, ~24, a net gain factor of up to 3 in the discovery rate could be
obtained, and yet a much larger factor for very high source redshifts. For
programs such as the GOODS/ACS transient survey, the discovery rate of
supernovae beyond z~2 could be significantly increased if the observations were
done in the direction of massive clusters. For extremely deep observations,
m_lim > 27 mag, or for very bright SNe (e.g. Type Ia) the competing effect of
field reduction by lensing dominates, and fewer supernovae are likely to be
discovered behind foreground clusters.
