Water-maser components in R Cas, whose peak flux density velocities V_los from Gaussian fits to maser emission components, are plotted against time. Sizes of the symbols are proportional to the peak flux density of the components. Solid blue and red lines are weighted least-squares fits to the components at ~24.5 kms⁻¹ and ~27.5 km s⁻¹, respectively. Fits are made separately for epochs 1 and 2 (see Fig. 7). Components that participated in the fits are indicated by red (27.5 km s⁻¹ component) or blue (24.5 km s⁻¹ component) crosses. The horizontal dashed line marks the stellar radial velocity V_*; the vertical dotted lines indicate the star’s visual maxima (AAVSO data).