How did Douglas remove his residual doubts about his fear of water?

Douglas removed his residual doubts by diving into the Warm Lake and swimming across to the other shore and back. He shouted with joy when he was able to achieve this feat. He had finally conquered his fear of water.

OR

Douglas first swam alone in the pool to remove his residual doubts about his fear of water. But then, when he still wasn’t sure, he went to Lake Wentworth, Triggs Island and Stamp Act Island. He swam two miles across the lake. Now, he was determined and he swam on. He shouted with joy as he had conquered his fear of water.