When Charlie Brown had hit the water, he had immediately fallen unconscious. Doing a back flop into the ocean really hadn’t been the safest way to go for a swim. As the children were watching the water, hoping for him to resurface, he was quickly being pulled farther and farther out into the ocean, and sinking deeper and deeper into the depths.
Within a minute, his lungs had begun to take in water. He was drowning.
But just as his brain was about to shut down from lack of oxygen, he was sucked through an invisible portal and emerged…somewhere else. The current carried him to shore, where he remained unconscious until somepony came to see if he was alright.