|"We're criminals, Farley. We believe in money - and survival."|
|— Crance to Farley, Glass Sword|
The Mariners are an underground group of smugglers, who run goods and sometimes transport people, in exchange of good payment. They command loyalty and respect and not even the Silver Security of the harbor bothers them. They are often at odds with their rival operation in the city, the Seaskulls.
As one of the three Red groups governing Harbor bay, the Mariners control a sector of the city, including the Fish Market. They operate from a battered, seemingly abandoned lighthouse with a view over the city, which they use as their base. They have access to the underground tunnels running below the harbor.
Members of the Mariners have a tattoo of a blue-black anchor, surrounded by red, swirling rope, typically on their forearm or upper arm.
In 320 NE, Egan and some members of the Mariners meet with Captain Diana Farley and Tristan Boreeve, the operatives assigned to Operation Red Web. The Mariners agree to help the Guard infiltrate into Norta. They accept to introduce them to the Whistle network and to let them use their own network to smuggle people.
Later that year, the Mariners betray Mare Barrow and her team when they ask them for access through the city, because Maven took Melody and is blackmailing the Mariners to bring him Mare. Also, Maven is offering a large reward for the capture of Mare and Cal. Shade Barrow and Farley, who had met Crance before, understand that it is a trap and a scuffle takes place, resulting in the deaths of three members of the Mariners.
When Crance and the group go through Paltry Place, Seaskull territory, five members of the Seaskulls follow them. They attack and beat up Crance and Shade, hoping to get a payment from Egan in exchange for their safe return, before the two manage to escape.