Not quite so obvious? Your body's survival mechanism would kick in and you'd probably change your mind and head for the shore which you may or may not reach, depending on your level of exhaustion.
Ever heard the term "weak in the knees"? This is something that happens with a near-drowning. It happened to me about ten years ago. I was caught in a rip and had just about lost hope when a guy on a surfboard fished me out. When I got to shore I couldn't stand up. I've seen other near-drowning victims react the same way.