In my campaign game this is a random encounter that you could face with a roll of a 6. Up to what is shown with an admiral and a spell caster just matching your fleet.
I will say that using a linen paper for the sails is absolutely the way to go, such a beautiful set of sails compared to just regular paper or even the sail sheet paper that comes with the new models.
And these are all magnetized and tomorrow I will spray them with varnish as I just put the sails on the galleon and finished painting the flag staff rods.