Five years ago, Hanan would never have dreamed that she would now be a swimming teacher. Fleeing IS from northern Iraq, in 2015 she crossed the Mediterranean with her family in a rubber dinghy. The boat filled with water, and Hanan couldn’t swim. She has an instant understanding with children who are afraid of water. Images of the vast blue sea and the fear of drowning are etched into her memory. Now living in Wolfsburg, Germany, she’s determined to have her younger brother learn to swim before his painful memories of the water rise to the surface, she says in an on-camera interview, as we follow her timid brother in the pool. The seahorse in the title refers not only to the creature that remains upright in the water, but also to the area of our brain, the hippocampus, where our memories are stored. This balanced documentary shows how water can take on a new meaning over time, and how swimming has become Hanan’s way of coping with trauma.