What are the motifs in The Mauritius Command by Patrick O'Brian?

The projection of naval power is a recurring idea. England is at war with France, and only England's superior naval force keeps French forces from invading and dismembering the British Empire. While France conquers most of Europe and reigns supreme on land, England's warships and hardy seamen rule the seas. Aubrey is an example of the type of naval commander and tactician that stymies Napoleon's aims on England, while Bonden and Spotted Dick are examples of sailors and minor officers that ably support their leaders. This theme is nowhere more evident than in the Admiralty's decision to effectively export England's naval power to Mauritius.