Complex sentence: In truth Cassidy awoke at dawn, still underwater but not having drowned or succumbed to his injuries he was understandably confused and afraid, several attempts to leave the water resulted in him catching fire in the sunlight and he waited until nightfall to leave the water.
Split into simpler sentences: In truth Cassidy awoke at dawn, still underwater but not having drowned or succumbed to his injuries. He was understandably confused and afraid, and his several attempts to leave the water resulted in him catching fire in the sunlight, so he waited until nightfall to leave the water.