In D M Turners book "The essential psychedelic guide", there is a chapter which is all about DMT and the "magical" link it has with water. Really interesting stuff. He goes on about how when he was exploring the Grand Canyon and he had some spice. He had a really negative experience. A few days later, he tried it again, this time it was worse. So he didn't do it for X months. Then one night him and his friend were on a boat. Some spice was going around, and he decided to have some. It was the most amazing thing he has ever experienced. Not only him, but all his friend who had some spice had amazing experiences as well.
He put it down to that when he was in the Grand Canyon (the desert), there wasn't a body of water for miles. Thus him having a negative experience. Yet, having it around the other way and being surrounded by water. He had the best breakthrough to date.