How do you get to dark link in the water temple?

Dark Link is located in the water temple in lake Hylia. First you must play the Serenade of Water to be transported to the lake. Then equip the Zora tunic and using the iron boots sink into the small puddle remaining in the now dried lake bed. This is the entrance to the water temple. Dark Link is located in a room with a diamond and several dragon heads in the center. Equipping the hammer for this battle will make short work of dark Link.