Spain's flotilla is kind of a basic model. She has
no special ability, aside from the abilities common
to all flotillas. She has the above-average cannons
of an offensive flotilla, which means you're better
off towing her into battle than dropping her
someplace to act like a fort. She'll add some real
kick to a Spanish battle fleet for only seven
points.
Of course, you can use her like a fort to bolster
your gold game if you want to. Spanish admirals all
play the gold game, right? Of course they do. So if
you want to guard an island full of doubloons with
this flotilla, or leave her to cover a choke point
so your gold ships can hide behind her guns, who's
to say you're wrong? For this low point cost, you
can use her offensively or defensively, and she'll
serve you just fine.