John D. MacDonald's Travis McGee is one such character.
Recently, Maynard MacDonald, the writer's son provided an in depth explanation of how and why the MacDonald estate came to their decision regarding the future of Travis McGee.
The cruiser has fought in many famous naval battles, yet few know their true function as a warship. The word "cruising" was used in the eighteenth and early nineteenth century to describe independent operations by a single ship, unattached to any squadron. "Cruizer" were usually frigates, sometimes smaller sloops and brigs. The essential meaning of the word was a description of function, not a classification of a ship-type. The cruiser's main task was to catch commerce raiding warships and to prey on enemy shipping. Source Cruisers by Anthony Preston