The Eyes of Sarsis by the late Andrew J. Offutt (
ISFDB,
Wikipedia,
SFE) & the late Richard Lyon (
ISFDB) is the 2nd novel in their War of the Wizards trilogy of swashbuckling adventure fantasy starring a young woman who goes adventuring on various quests to find items and defeat evil, as you do, this one a properly piratical adventure as the heroine, now Captain of a pirate ship

, is asked to take up the quest of a King's lost daughter and defeat the terrible magical thingamajig which was unleashed by an earlier attempt to regain her, free for a limited time courtesy of publisher Endeavour Press' Venture imprint.
This was originally published in 1980 by Pocket Books.
Currently free @
Amazon (available to Canadians & in the UK and pretty much everywhere else worldwide that Amazon sells, since this is being done via their KDP Select exclusive or else program)
Description
A strange white cat wandered about the streets of Reme while Captain Tiana Highrider, master of the pirate ship Vixen, held court.
The red-haired beauty was queen of the pirates and had seen many strange things throughout her adventures, but when a harmless blind beggar moves with the certainty of his sighted days, her instincts are prickling.
Suddenly, she and her adopted father, the mighty Caranga, are brought before the king and asked to take up the quest to return his kidnapped daughter. The king also tells of a dark power he unwittingly unleashed in his desperation to have his daughter returned; the Eyes of Sarsis – a dark power even the most commanding of magicians desire to remain buried in the earth.
At the same time, more mysterious things are happening through the city – animated bodies, mysterious orders, corpses without blood – and at all, a white cat lurks in the shadows.
Tiana’s thirst for adventure and the promised reward lead them through the city, out onto the open sea, into dangerous territory, and seeking strange lands in the quest to return the king’s daughter, find the stolen treasure, and most of all, defeat the Eyes of Sarsis, a power no man can break.
Along the way they ally with strong barbarians, magicians, unknowable creatures, and ancient beings to fight the awful power of the vampiric Eyes…