The Water Lord is a class which is, quite simply, more powerful when near or in water. Being a caster, their are a number of water related spells at the caster's disposal. When the caster is within 50 feet of some kind of water source (be it the sea or even a small pond) the player receives a buff, increasing damage done and reducing cast time.
The class wears cloth, and would be available to Blood Elves, Humans, Trolls, Tauren, Dranei and Gnomes.
Water Jet: 2 second cast ranged spell, dealing 600 damage to a target.
Tsunami: An AOE attack where water rains down. 800 damage over 10 seconds.
Soak: A debuff which slows the enemy movement speed and reduces armour.
From the depths: Summons a random sea creature to attack the enemy. Sometimes a weak melee turtle with high armour, sometimes a Murloc with average stats and sometimes a naga with ranged attacks.
Although the class appears to play like a mage, it is actually a lot more focussed on buffs for the party/raid and debuffs for the enemy, most of these not dealing much damage on their own. When combined with the other Water Lord attacks, the class becomes stronger.

An example of a Water Lord.