How do I win in ship-to-ship combat?

Hint 1 of 4:

First of all, you need to find a well-matched opponent.  The stronger pirates
have cannons with longer ranges, so they're harder to fight.

Hint 2 of 4:

In order of increasing difficulty, the pirates are Not Really Fearsome
Pirates, Semi-Fearsome Pirates, Mildly Fearsome Pirates, Pretty Fearsome
Pirates, Fearsome Pirates, Really Fearsome Pirates, and Captain Rottingham.

Hint 3 of 4:

Start with the easier pirates and work your way up.  You can take the
treasure you win and cash it in at Puerto Pollo for better weapons, which
then allows you to fight stronger pirates, etc.  There are a total of 7
strengths of cannon -- which seem to match the different levels of opponents
as well.

Hint 4 of 4:

I recommend trading up your cannons after each you defeat each pirate both in
ship-to-ship and sword combat.  That way, your hold will always be empty if
you lose to a pirate in a sword fight.  Each victory entitles you to one
upgrade.