Instructions
Purchase an Elixir of Water Walking from the auction house if you do not have a spell that allows you to hover over the water, such as Levitate or Water Walking.
Equip an item that grants you the slow fall effect if you do not have a slow fall spell. The slow fall effect decreases the rate at which you fall. Slow fall items include Skyguard's Drape and the Parachute Cloak. Certain classes have slow fall spells, such as the Mage's Slow Fall spell.
Invite a friend to form a group and convert the group to a raid. Enter Coilfang Reservoir in Serpent Lake in Zangarmarsh. Enter Serpentshrine Cavern, which is the middle dungeon entrance once you enter Coilfang Reservoir.
Take the elevator to the bottom floor. Take the right path once you exit the elevator. Continue on until you reach a ramp. Go up the ramp and take another elevator to the next floor. Exit the elevator and press yourself against the left wall. Walk to the ledge. Cast your water walking spell or drink a water walking elixir. Enable your slow fall effect and jump off the ledge. You will glide through the air, eventually descending onto the water.
Run slightly northwest, but keep your direction mostly to the west. You'll pass under numerous bridges and ramps. Eventually, you'll see multiple wooden planks that form a circle in the water. In that circle is a blue aura. Jump onto the planks.
Stand near the edge of the blue aura and begin fishing. Eventually, you'll fish up The Lurker Below. You will die even if you attempt to run away unless you're level 85 or above. Remove your armor and place it in your inventory before fishing to avoid incurring damage to each piece of armor.