Integrated H I emission (moment 0) contours overlaid on a DECaLS r-band image. HCG members are shown with blue contours, extended features in green, and non-member galaxies in red (none in this panel). The VLA synthesised beam is shown in the bottom left as a solid black ellipse and a scale bar indicating 20 kpc is in the lower right. The contours start at 4σ (over 20 km s⁻¹) and each subsequent contour is double the one before it. The minimum contour level is listed for each group in Table 1.