Just Stop Oil activists blocked a coach carrying asylum seekers back to the Bibby Stockholm accommodation barge on Thursday 19 October.
Migrants are returning to the vessel today, following the discovery of Legionella bacteria in the water supply in August.
Footage shows a number of protesters standing in front of the coach with a large sign that read “no prison ships”.
Just Stop Oil claimed on social media website X that supporters had blocked the only road access to the boat in Portland, Dorset.
A second statement from the group, shared shortly after, claimed the coach driver had “rammed through” their block.