This chapter traces a single motif—that of the ‘Ocean’—within Seneca’s Suasoriae. This theme spans the declamations of Argentarius, Pompeius Silo, Moschus, Musa, Albucius Silus, and Papirius Fabianus, as well as verses by Albinovanus Pedo and excerpts from the History of Alexander by Quintus Curtius Rufus. By comparing how these declaimers and authors introduce variations around the idea of an ‘ocean’ while maintaining its overall characteristics (e.g. darkness, monstrousness, sluggishness), this chapter identifies two overarching concepts which governed declamatory improvisation. On the one hand, ‘scalability’ allowed declaimers to compose speeches of different lengths while maintaining thematic coherence through the use of similar core-structures; on the other, the principle of ‘sequence’ dictated that each declaimer spoke in response to another. These parallel concepts enabled declamatory themes to gain new meanings through an ongoing accumulation of arguments and contributed to declamation’s status as a dynamic, interactive process.