  Although comparatively bright, the cataclysmic variable GY Hya has not
attracted much attention in the past. As part of a project to better
characterize such systems photometrically, we observed light curves in white
light, each spanning several hours, at Bronberg Observatory, South Africa, in
2004 and 2005, and at the Observat\'orio do Pico dos Dias, Brazil, in 2014 and
2016. These data permit to study orbital modulations and their variations from
season to season. The orbital period, already known from spectroscopic
observations of Peters & Thorstensen (2005), is confirmed through strong
ellipsoidal variations of the mass donor star in the system and the presence of
eclipses of both components. A refined period of 0.34723972~(6) days and
revised ephemeris are derived. Seasonal changes in the average orbital light
curve can qualitatively be explained by variations of the contribution of a hot
spot to the system light together with changes of the disk radius. The
amplitude of the ellipsoidal variations and the eclipse contact phases permit
to put some constraints on the mass ratio, orbital inclination and the relative
brightness of the primary and secondary components. There are some indications
that the disk radius during quiescence, expressed in units of the component
separation, is smaller than in other dwarf novae.
