A hard taskmaster, Bapi is the person who runs Nailer's light crew. He's on Nailer to make quota at the beginning of the novel, and he serves as a mouthpiece to give us some context about Nailer's father. He dies in the city-killer storm that levels the area of Bright Sands Beach.
Blue Eyes is a pretty scary member of Richard Lopez's crew. She's tattooed and scarred and has made gifts to the Harvesters and Life Cult (most likely giving a kidney and the eggs from her ovaries), which makes her dangerous. When Nailer is trying to free himself, Nita, and Pima from his father's goons, he tries to kill her. She threatens to take an eye, but Sadna saves Nailer.
Unfortunately, Blue Eyes overpowers Sadna, but Nailer sneaks up behind his father's henchman and slits her throat before she can kill Sadna.
It takes Blue Eyes a while to die, but her death serves as a useful stepping stone for thematic discussions of violence, humanity, and who deserves to live and die.
He's the captain of Dauntless and one of the few clipper captains that Nita can trust. At first, he doesn't trust Nailer at all, thinking he's just a ship breaker with no redeeming qualities, but as Nailer tries to fit in with the crew, the Captain gives him a knife and gun to use during the final skirmish and allows him to help out on the ship.
Although intelligent, the captain is duped into a trap by the Ray and Pole Star, ships commandeered by Nita's enemies. He decides to trust Nailer's advice about sailing into the Teeth, and while his maneuvers cause the Pole Star to founder and start to sink, he is shot in the grand standoff. Fortunately, though, he survives.
A half-man like Tool, Knot's patron is Captain Candless. He works in the hydraulic system room of the clipper ship and teaches Nailer to read. He's more of a traditional half-man, loyal to his patron and willing to die for his master. He serves as a contrast to Tool so that we can see how remarkable Tool's individualism really is.
Everyone wants to be Lucky Strike. He's a guy who found a cache of oil and squirreled it away to buy his freedom from heavy crew that breaks down the ships. Now he capitalizes on everyone else's need to remain in power. We're told:
His hand was in the gambling dens and the nailsheds and a dozen other businesses, and the money just rolled in. […]
He was smiling and looked confident, but he had a line of hired goons standing behind him to back up his authority. (7.17, 18)
Charming, right? Not so much. Lucky Strike always comes out on top because he is lucky to some extent, but mostly because he is savvy. He finds a need and exploits it, even ingratiating himself to Nita's crew at the end of the novel. We get the feeling that Lucky Strike will be in power for a long time.
He's a "business-marriage uncle," probably someone who makes deals for the company. He was working for Nita's father, but decided to use some of the company's resources for his own gain, and now he wants to use Nita to pressure her father to allow him to refine tar sands; thus, the relentless pursuit of her. Patel doesn't want to do this, so Pyce has been skirting the laws by using the black market, refining the oil and selling it to China where it's not traceable. At the end of the novel, it's implied that Pyce has gotten his comeuppance, though we never really know what happens to him.
One of Candless's crewmembers, Reynolds is a short and stocky midshipman, er, woman. She commands some authority, which she demonstrates when gathering the crew to find Nita in Orleans. She seems to be a second-in-command figure after Captain Candless, especially after Candless kills the lieutenant who was ratting him out to Pyce's men. She's kind to Nailer and decides to give him a chance to work on Dauntless.
Though she only appears for a short time, Sloth is important to the novel in that she helps Nailer make the choice to rescue Nita. Wiry and spry, Sloth wants Nailer's spot on light crew, and she's willing to betray him to get it: She leaves him to drown in a vat of oil.
When Nailer escapes and returns to Bapi, Sloth is kicked off light crew and condemned to a hard life. She's proven herself to be untrustworthy, and, because of this, her options are few and unfortunate—she can basically either sell her body parts or sell her body in prostitution. Either way, she's chosen a difficult path. She disappears after the storm, never to be seen again.