We can infer from the passage that ………….

In one of the counselling sessions following the
incident Don said, “ I had lived on the ocean all my life.
I had seen lots of people get drowned. I had made up
my mind what I'd do if I ever got caught myself.” He
would swim out past the breakers until the tide
changed, save his energy by merely keeping his head
above water as he floated on the waves, and then
swim in with the incoming tide. This was the plan, he
actually followed, and this was why he remained far out
in the ocean for such a long time that his friends
thought he must have drowned.