Wintrow Vestrit is the eldest child of Keffria Vestrit and Kyle Haven, and the older brother of Malta and Selden. He intends to become a priest of Sa, but this plan is derailed when his father inherits the Vestrit family liveship Vivacia and forces Wintrow to serve aboard her.
Wintrow is fourteen at the outset of the series, but appears much younger, being short and thin for his age. He has dark eyes and hair and his father's fair Chalcedean complexion. He is said to strongly resemble his aunt Althea. In Ship of Magic, he is forcibly tattooed on his face with both the Satrap's mark and a portrait of the Vivacia's figurehead. He also injures his right index finger in an accident on the ship, and has it removed. In Ship of Destiny, a healing meant to undo the effects of serpent venom also expunges the tattoos from his face.
Wintrow is very reserved, preferring the quiet of the monastery to ordinary life in Bingtown. He is thoughtful and reflective to the point of alienating himself from others.
Wintrow, who is living at a monastery, is disappointed when informed that he must return to his family's home in Bingtown to witness the death of his grandfather. There, Wintrow's father Kyle Haven is granted ownership of the Vivacia. Kyle attempts to force Wintrow to complete Vivacia's quickening, but Wintrow refuses, insisting that it is not his right. However, Kyle forces Wintrow to sail with him to fill the role of the blood relative that must remain aboard a liveship.
Wintrow finds it difficult to find acceptance within the crew, and he is mistreated by his father and the first mate Torg. Wintrow struggles with integrating his religious habits and beliefs with the day-to-day life and culture aboard a ship. He discovers that life outside of the monastery is far different than he expected.
When the Vivacia docks in Jamaillia City, Wintrow dons his robes again and escapes, despite the ship's pleading for him to stay. He passes through the slave markets and observes a dying woman, who begs for his assistance as a priest. Wintrow eases her pain and she dies peacefully, but the slaves' owner is enraged at her passing and claims that Wintrow is responsible for his loss of property. Wintrow is imprisoned and informed that if no one comes to collect him within three days he will be auctioned off.
On the third day, Torg sees Wintrow in the cell, but ignores his cries to be freed. Wintrow is tattooed with the Satrap's mark and sent to auction, where his father and Torg are buying the last of their cargo. Wintrow fears that his father will allow him to be sold away, but Kyle eventually purchases Wintrow, although he starts the bidding at an insultingly low sum. To Wintrow's horror, Kyle has him further tattooed with a portrait of the Vivacia's figurehead, declaring him the liveship's own slave.
Both Wintrow and Vivacia are quickly demoralized by the misery of the slaves aboard the ship. Although Wintrow is not shackled below decks, he has lost nearly all respect and acceptance from the crew. Wintrow frequently visits the slaves to bathe them and soothe their wounds or illnesses. He is approached by the former priest Sa'Adar, who begs Wintrow to help the slaves stage a rebellion, unaware that Wintrow is the captain's son. Wintrow refuses, but brings the mate Gandry below decks, where the slaves seize his lantern and kill him, freeing themselves.
The slaves commence a revolt, killing most of the crew and attempting to command the ship for themselves. The stormy weather and Vivacia's distress at the bloodshed on her decks makes the ship veer out of control, and Wintrow takes the wheel himself, preventing Vivacia from capsizing. '
The slaves recognize Kennit's flag on the ship that follows them and allow him to board. When Kennit seems about to allow the slaves to kill Kyle, Wintrow threatens to kick him in his injured leg. Kennit seems impressed by Wintrow, and states that he will allow Wintrow and his father both to live if Wintrow successfully operates on his injury. Wintrow is doubtful of his own medical ability, but has no choice but to accept.
Wintrow amputates Kennit's leg using the training he received at the monastery. The surgery appears to go well, but Kennit later dies. Together, Wintrow and Vivacia return Kennit to his body. Wintrow briefly experiences some of Kennit's memories.
With the successful surgery, Wintrow ensures survival for himself and his father. Kyle is kept prisoner in one of the ship's cabins, and rejects Wintrow's attempts at politeness. Wintrow is disappointed by this. However, when Kennit abandons Kyle on Key Island, Wintrow is aghast. He does not believe Kennit's promises that his father still lives.
Wintrow begins to spend much time with Kennit. Although Kennit's rejection of Wintrow's faith and religious principles initially perturbs Wintrow, he begins to find Kennit's beliefs logically sound.
Kennit pushes Wintrow and Etta to each other's company, intending that they conceive a potential heir that Kennit might use to control Vivacia if he cannot bend Wintrow to his will. Wintrow begins to teach Etta to read. Although she struggles, she is grateful for his attention to her, and the two begin to bond. In return, Etta goes to Wintrow's rooms at night and teaches him to fight with a knife.
Wintrow goes ashore with Kennit when they return to Divvytown, which has recently been raided. The crowd accuses Kennit of bringing the destruction upon them, and tries to attack him. Wintrow defends Kennit, using Etta's lessons for the first time. Wintrow then gives an impassioned speech calling on the residents of Divvytown to rebuild their city, which renews their loyalty to Kennit.
Wintrow's actions make Kennit view him as his own personal prophet, and Wintrow is brought to Other's Island to receive a soothsaying. Wintrow walks the Treasure Beach alone, and chooses a path which leads towards black rocks. He discovers a serpent imprisoned in a cell carved into the cliff face. Wintrow removes the bars of the cell, and while the serpent is escaping, its body makes contact with Wintrow multiple times. Wintrow experiences a flood of serpent memories from She Who Remembers, which renders him near-insensible, and her venomous slime causes his skin to swell, blister, and slough off.
The Abominations attempt to prevent She Who Remembers from escaping on the tides, but fail with the interference of Kennit and Etta. They swim Wintrow's body to a rowboat while his mind is overcome, and, with the assistance of She Who Remembers, return Wintrow to Vivacia's decks.
Wintrow languishes aboard the Vivacia, deliberately preventing his mind from surfacing for fear of the pain his body is in. He makes contact with the spirit of the dragon that lived within Vivacia's timber and discovers the truth of liveships. He fears awakening and imparting this knowledge to Vivacia. With the dragon's guidance, Wintrow manages to perform something akin to a Skill-healing upon himself, though the dragon stops him when he has recovered enough to regain consciousness. Upon awakening, Wintrow makes contact with Vivacia, and the ship is thrown into distress upon learning that she was originally a dragon.
The ship's personality is subsumed by that of the dragon, who calls herself Bolt. Wintrow is distressed by the loss of Vivacia and finds himself at odds with Bolt. Bolt suggests that Wintrow ally with her to become a Skill-healer in his own right, but he refuses. The dragon then manipulates Wintrow's vulnerability to her through the link they share and makes him lose consciousness. The dragon aids Kennit in performing a full Skill-healing on Wintrow against the boy's will, which restores him to full health. Even Wintrow's tattoos eventually disappear, though the healing does not regrow his missing finger.
Wintrow struggles to connect with Bolt, missing Vivacia as Bolt and Kennit grow closer. During this time, Wintrow becomes closer to Etta, who is also left lonely by the ship's monopolization of Kennit's attention. Etta confides to Wintrow that she is pregnant; Wintrow surprises himself by becoming jealous.
Amber, who had been associating with Althea Vestrit while seeking a "nine-fingered slave boy," meets Wintrow for the first time and immediately recognizes him as the person she had been searching for, much to Wintrow's puzzlement.
Wintrow is mentioned in Blood of Dragons as continuing to captain the Vivacia as the consort to Etta, who is referred to as the Pirate Queen. They continue to raise Paragon Ludluck, Kennit and Etta's son.