Airborne imagery of a disintegrating Sargassum drift line

► A Sargassum drift line disintegrates under a wind speed of 5 m s−1. ► Weed left behind more rapidly drifting rafts form long upwind 'trails'. ► Wave drag may be creating a distinct raft-and-trail morphology. ► Remnant frontal accumulations of only submerged Sargassum occur upwind.