In Greek mythology water nymph refers to a class of minor deities associated with rivers, streams, ponds, lakes, fountains or the sea. The word "nymph" comes from Greek and simply means a young girl. The Greeks have many myths about nymphs and distinguish different types: sea nymphs (two types: oceanids and neriads), fresh water nymphs (naiads), forest nymphs (dryads), tree nymphs (hamadryads).
There were fifty Neriads, the daughters of Nereus (who was called the Old Man of the Sea) and Doris (the goddess of the bounty of the sea). They were particularly associated with the Aegean Sea and usually accompanied Poseidon. They were known to be helpful to sailors, especially during storms.
The Oceanids were daughters of the Titans Oceanus and Tethys, and there were three thousand of them! Each was associated with a specific lake, spring, river or pond; they were also associated with non-water-related things like flowers, pastures and clouds. One of the Oceanids was associated with "luck" (Tyche), and one with "persuasion and seduction" (Peitho).
Water, in all it's forms, is so important to human life that every society has it's myths about it and the magical creatures associated with it.
Generally speaking, the Greeks have the classiest myths around, and the most complex. The various gods are like characters in a long novel about a big, quarrelsome family that covers several generations. The myths about the major gods for example cover at least three generations: Gaia and Uranus (literally earth and sky), their children the Titans which include Hyperion, Coeus, Oceanus, etc., and their children the Olympian gods like Zeus, Hera, Aphrodite, Apollo and such.
If you study the myths closely you will see that they are all interrelated.
represents the saltiness of the sea
from the Odyssey
nymph loved by Apollo
does the name sound familiar?
Swedish mythology water nymph
from Asturia (not the one in Queens)