Complex sentence: Canton realizes the ship is sinking, and thinks all the witnesses will die, and that he will collect the insurance money after all, and plans to abandon the others and use a jet-ski to get to an island visible in the distance.
Split into simpler sentences: Canton realizes the ship is sinking, and thinks all the witnesses will die and that he will collect the insurance money after all. He decides to use a jet-ski to get to an island visible in the distance.