Chapter 8 focuses on State practice, with an emphasis on acts taken unilaterally by States in disputed maritime areas, due to which a conflict has arisen in bilateral relations. To provide the most complete picture of acts undertaken unilaterally in disputed waters, examples have been collected from two types of disputes: first, where disputes to title to territory underlie the disputed maritime areas; and, second, where overlapping claims to maritime zones exist. Unilateral conduct in disputed maritime areas is not exclusively concentrated to certain parts of the world. Varying extents of conflicts are created in State practice when activities under the authority of the coastal State – including concessioning, seismic work, exploratory drilling, exploitation, marine scientific research and fisheries activities – are undertaken unilaterally in a disputed maritime area. Reacting to such a unilateral act is often seen as vital by a claimant State, and these reactions can take various forms, including law enforcement. Acting in response might be a double-edged sword, however, as this reaction can sometimes set in motion a spiral of action and reaction, whereby each State feels obligated to react to the other’s act, so as to defend their sovereign rights and interests.