Ball Python in his water?

Question
My ball python has a rather large enclosure. He's about one year old. On one corner I have a heat bulb over a rock, and next to that there is a tunnel with a heat pad underneath. Two questions!

1.) Is this too much heat?
-AND!-
2.) Is it alright that lately he perches across the ledge of his water dish and leaves his rear end submerged? (It is a rather large water dish, I'd say it's four inches deep and six inches either direction.)

I'm sorry. I try to learn as much as I can to take care of my snake but sometimes I just have a question.

Answer
As long as the snake can choose a hot side and a cool side and the ambient temp is between 80 and 85 (or a reasonable gradient between the two), I'd say the heat is just fine. Make sure you have the humidity correct as well. I would say that it is fine that he perches that way. As long as he is eating good, I would not worry too much. The first sign (75% of the time) that something is wrong? They quit eating for an extended period of time.