As Raze said, stand west of the red flag, turn into a ghost, and head west. At level 2 ghost, I stayed a ghost for plenty of time to pass over the lake before turning human again. In fact, I had to stand around and wait to turn back to human. Make sure you are clear of the water. Also, your mana comes back after you turn human again and you also get use of your skills again. As soon as I turned human, I paused the game and selected my active skill.