Emerald Ocean is one of three oceans released on January 31, 2012. The ocean is a doubloon ocean created through the merger of the Sage and Hunter Oceans, and open testing lasted from January 17 to 24, 2012.
The mergers of the English-language oceans were hinted at on December 7, 2011, when the "Intrepid Explorer" Velasco Thorsson posted his journals on the Hear Ye! Announcements forum. The mergers were subsequently announced the next day by Hermes. On the same day, voting on the new oceans' names opened to the general public, who voted on the name "Cerulean" for the new subscription ocean, "Meridian" for the Viridian/Malachite merger, and "Emerald" for the Sage/Hunter merger.
Emerald has ninety-two islands divided among fifteen archipelagos. There are fifty colonized islands.
The archipelagos in the former Sage Ocean are named after birds, and the islands in those archipelagos are named after places—both real (Ashkelon Arch) and fictional (Morannon Island)—or people (Jack's Last Gift). Similarly, the archipelagos in the former Hunter Ocean are named after astronomical features (e.g., the constellation of Orion, the Pleiades open cluster, the Horse Head nebula), and the islands in those archipelagos are named after a variety of things including places—both real (Anegada Island) and fictional (Lyonesse Island), and especially from mythology and folklore—people—again real (The Beaufort Islands) and fictional (Ix Chel), and again especially from mythology and folklore, like the latter—and loanwords from other languages—once again both real (Matariki Island, from the Maori) and fictional (Umbarten Island, from Tolkien's Elvish).