Elemental Plane of Water

It is an ocean without a surface. It is domain of current and wave. It is a bottomless depth.

— Wanderer of the Planes

There was no deep or shallow, no dark depths nor wavy surface, just an endless ocean that felt as if you were submerged several feet (say a couple meters) in any body of water. There was no sun, yet the water itself seemed to glow dimly with a bluish green luminescence. Volumes of water at any temperature and salinity could be found if you knew where to look or had a guide. Life that depended on particular conditions flowed along with their preferred environment or suffered the consequences. Impurities such as bubbles of air, chunks of earth, and even short-lived balls of fire could be found floating about due to elemental vortices or the workings of powerful beings.
Supporting the teeming life of this plane were the corals and plants that made their way here and found purchase. Huge drifting three-dimensional reefs and loose spheres of freshwater grasses, kelp, and seaweed were home to myriad species and were fertile fishing spots. Travelers had to keep in mind that large predators knew of these fishing grounds also, or else they might discover just how bite-sized they actually were. Just like a Prime ocean, the Elemental Plane of Water seemed to have no limit on how large some creatures could be. Small creatures could be deadly too, with poisonous spines or barbed tails. The smallest of them all was perhaps the deadliest: algae that formed the infamous "red tide". Exposure of the eyes or lungs to the red tide caused a blinding sickness as virulent as any disease.
If the Plane of Water had any weather, it was the currents, whirlpools, tidal bores, and flows of ice, steam, or silt that could inconvenience a traveler or be a deadly surprise. Usually invisible, currents could be strong enough to pull visitors off in some direction for long distances before they were able to exit the current. Tidal bores were the most dangerous currents, hitting like a thrown boulder and carrying the unlucky creature away for miles (kilometers). Whirlpools were caused by countervailing currents that sucked everything in a tightening spiral, some of which lead to vortices to other planes. Ice and silt flows were fairly easy to spot before encountering, but steam flows were nearly undetectable and could cause nasty burns or boil the flesh from your bones.

Inhabitants

It is difficult to determine what type of creatures were the most numerous in the Elemental Plane of Water but presumably the water elementals had the upper hand because they were manifestations of the plane itself.
Almost any concievable form of aquatic creature could be found somewhere in the plane. But more notable inhabitants included nereids, tritons, sea-hags, aboleths as well as aquatic elves.
The genies of the plane were called the marid, who were unpredictable but proud. In a sense, the marid were the most "equal" of the genies, in the sense that they saw all other beings as inferior to themselves.

Languages

Aquan

Color Pools

Dark Blue

Ethereal Curtains

Flickering blue or green

Tuning Fork

Lead, A

Shape and Size

Infinite

Gravity

Subjective Directional

Time

Normal

Type

Dimensional plane