  We have used spectrophotometric data from the Hubble Space Telescope to
eclipse-map the primary component of the RS CVn binary SV Cam over 9 HST
orbits. We find from these observations and the HIPPARCOS parallax that the
surface flux in the eclipsed low-latitude region of the primary is about 30%
lower than computed from a PHOENIX model atmosphere at the effective
temperature that best fits the spectral energy distribution of the eclipsed
flux. This can only be accounted for if about a third of the primary's surface
is covered with unresolved dark star-spots. Extending this to the full surface
of the primary, we find that even taking into account this spot filling factor
there is an additional flux deficit on the primary star. This can only be
explained if there is a large polar spot on the primary star extending from the
pole to latitude 48 degrees.
