Green Maelstrom was a gigantic green-gray colored whirlpool located somewhere within the the northwestern seas of Southsward. It made the fastest part of the Roaringburn current. This whirlpool had a reputation for being entirely impossible to navigate as it had claimed many ships. After Finnbarr Galedeep and his crew reclaimed the Pearl Queen, Strapp took his ship, the Shalloo, and went in pursuit of the Pearl Queen to capture it for himself. However, using some skillful maneuvering, Finnbarr veered away from the Maelstrom, and that left the Shalloo and its two crews to be swallowed up and die in the Maelstrom. The whirlpool creates a strong current that goes Southsward, on which the Pearl Queen sailed on.
The Green Maelstrom appears in The Bellmaker.