A couple of Robert Brightwell's (Thomas) "Flashman" series* have the eponymous hero as a shipmate of Cochrane - first in the Mediterranean in "Flashman and the Seawolf" [0] and later in South America in "Flashman and the Emperor" [1]

Both are great rollicking action adventures.

* Thomas is the uncle of the more famous Sir Harry Paget Flashman, V.C., whose memoirs are edited by George MacDonald-Fraser.

[0] https://robertbrightwell.com/my-books/flashman-and-the-seawo...

[1] https://robertbrightwell.com/my-books/flashman-and-the-emper...