What is the setting of Hornblower and the Atropos by C.S. Forester?

The primary setting of Hornblower and the Atropos is the decks of the Atropos, as Hornblower and his men travel the high seas. Other location include but are not limited to Gibraltar, Cartagena, Cape Ferro, Palermo and Sicily, Malta, Rhodes and most significantly Marmorice Bay.