Gentle Ben

Mark befriends a boy whose family is vacationing on a houseboat in the river. While out on an adventure together a hurricane quickly comes in. They get the boy's mother from the houseboat and Ben leads them to the safety of a cave.

A dolphin comes up the channel and hangs around the Wedloe's dock. He and Ben become friends and Mark considers him his pet. Mark is disappointed when he finds out that the dolphin escaped from Miami Seaquarium and has to go back before he is lured by the wild dolphins at sea in mating season. The lure of mating season is too strong for the dolphin, Marco Polo, and he heads to sea with Ben following.