The sea elves or water elves (vatnalfar) go by many names in many places. The Achaeans and Southrons call them Sirene, or Sirens, and fear the females for their enchanting songs that can lure hypnotized sailors to their doom on sharp sea rocks. The males have also been known to board and raid ships while the crew stand enchanted by the females' songs. They have also been known to dwell farther inland, in the beds of rivers, luring the unwary beneath the waves to be drowned. Some call these kinds river nymphs. Although some sea elves are malevolent, but most merely wish to defend their territory from intrusion by foreign invaders and meddlers. Despite their ability to remain beneath the waves for a seemingly indefinite amount of time, they do not have gills, and must occasionally surface for air, unlike their merfolk neighbors.


Most Sirene do not live to be as old as other Alfar races. The light elves look down on them as too "earthy" and less "divine" than themselves, and to an extent this seems to be true - though the Sirene may live for centuries, few if any ever reach the elder ages of the Ljosalfar or ascend into Alfheim, though it is still possible.


Sea elves are about the same height as Achaean humans. They are very vibrantly colored and appear far stranger than most other elven races, what with their almost endless variety of hair colors (green, blue, red, black, blonde, or brown). Their eyes are usually blue, green, or grey: the colors of the sea. Their skin is often light and like that of a Western human's, but some have very oddly-tinted skin such as bright blue, turquoise, or grey; some sirens that dwell in marshy areas and riverbeds have greenish skin.


Sea elves are as reclusive as dark elves, and nearly as malevolent from a human point of view, due to their tendency to wreck any ships that approach their islands. In reality, they simply want to be left alone. They live in harmony with the sea and its creatures, and will defend sea life - such as a pod of whales - from hunters with deadly force. Some dwell in coral cities that stretch from rocky sea caves to underwater gorges, partially above and partially below the waves. They have good relations with their neighbors, the merfolk, although the two races are not related. Merfolk are descendents of the Shifters rather than alfar. Sailors are seldom well-learned enough to make this distinction, and often the two races are confused.


They favor the Nordic god of the sea, Njord, but due to their relationship with the Poseidon-worshipping merfolk, they occasionally worship the Imperial sea-god as well, along with other minor water-related deities. They have been known to breed pegasi on their well-protected, secret islands, and it is said that all of the high elves pegasi are purchased or borrowed from the sea elves. This, as well as confusion with harpies, has given rise to some legends depicting them as winged women, when in fact they do not posess wings.


Sea elves sometimes wear armor made from the shells and hides of sea creatures, from coral, or even made by other elves or sea dwarves with whom they have traded. Like the merfolk, their favored weapon is the spear, which they can throw with stunning accuracy, even underwater. They also employ bows, but only rarely do they use metal weapons or armor. They have been known to ride sea creatures like mounts from time to time, even sharks, in addition to their beloved pegasi, which they protect with their lives.