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The Sea Bitch is a new longship built by Sigrin. It has a lean, black hull a hundred feet long, a single mast and fifty oars. The longship has a deck large enough to hold a hundred men and an iron ram shaped like an arrowhead.
A Clash of Kings
Theon Greyjoy is given command of the new longship at Lordsport after he returns to Pyke. He names it Sea Bitch after Esgred (actually his sister Asha) claims the longship is a sea bitch instead of a fair maiden.
Theon sails the Sea Bitch as the flagship of his force that harries the Stony Shore. Deviating from the plan of his father Balon, King of the Iron Islands, Theon grants six longships to Aeron Greyjoy to continue raiding the shore but keeps the Sea Bitch and Dagmer's Foamdrinker. While Dagmer threatens Torrhen's Square and distracts Ser Rodrik Cassel, Theon is able to capture capture Winterfell.
Theon: I would never mistreat such a fair maiden.
Asha: Fair maiden? She's a sea bitch, this one.Theon: There, and now you've named her. Sea Bitch.