Who is Brown from Ship of the Line and what is their importance?

Brown is the coxswain. In the latter half of the novel, Hornblower selects Brown to assemble the crew used on the swimming raid, whose goal was to burn a French coaster. His performance so impresses Hornblower that he later has Brown throw a towline to the disabled Pluto. Hornblower admires Brown's easy competence at any physical task, and he is envious of his physique.