On the bottom of the Baltic Sea lies thousands of naval mines left after the World Wars, threatening to detonate. The sea is also threatened by heavy pollution and by studying its changes it is possible to predict what will happen to other oceans in the future. A Wine-colored Sea is a poetic and associative odyssey through a Baltic Sea where clearance divers are looking for mines, dolphins are thriving and where algal blooms are causing color shifts in the water. The film focuses on themes such as vision, illness, threats, and the gaps between description, depiction and experience. The visual material is showing techniques that are used to map the sea bottom for different reasons, and how these techniques are connecting different senses, as for instance in sonars where sound waves get translated into images. Through the text, an ambiguous ”we” is speaking – a collective underwater voice.