Why did Douglas go to Lake Wentworth in New Hampshire? How did he make his terror flee?

Hint: This question is taken from the chapter ‘Deep water’. Here, the main focus of the question is to ask that even after completing his training, why does the protagonist choose to go to New Hampshire. There have been several attempts made by him to make his terror flee but we have to only focus on those ones where he is in New Hampshire.

Complete answer:
Douglas was not sure whether all the terror had left even after the training from October to April and practice till July. From October to April Douglas did extensive training to overcome his fear of water. After he completed his training he wasn’t scared of water anymore but he wanted to push his limits and challenge himself.

So, he went to Lake Wentworth and swam two miles. Terror returned only once when he was in the middle of the lake. He had put his face under and saw nothing but bottomless water. The old sensation returned in a smaller size. He laughed and rebuked terror. His terror fled away and he swam on.

Note: This incident takes place after Douglas completes his training and not before. He chooses to swim in the lake because he is unsure about his fear of water. The horrors of his past are a huge motivator for him to make this decision. It can be concluded that Douglas is a very determined person with nerves of steel.