Optical, H I emission and velocity field of NGC 1427A (top) and NGC 1365 (bottom). Left: FDS g-band image with the 3σN_{HI, 25 km s⁻¹} = 2.7 × 10¹⁸ cm⁻² contour overlaid. The H I-detections are coloured according to their integrated M_HI, where galaxies are labelled and shown with open contours and H I clouds are filled. Right: Velocity of the respective fields. In all images, the 43″ × 40″ beam is shown in the bottom left, and a 20 kpc scale bar is shown on the bottom right. With respect to NGC 1427A and NGC 1365, the H I clouds have similar velocities and show a continuous gradient.