The 'man on a boat story' could be about a man who simply loves being on a boat. He might be sailing for the pure joy of it. He could be observing the marine life, like dolphins swimming alongside his boat, or seagulls flying overhead. He may also be trying to reach a particular destination, a secluded beach perhaps, where he can relax and be alone with his thoughts. It could also be a story about a man who is on a mission on his boat, like delivering important goods or even rescuing someone lost at sea.
I'm not sure specifically which 'man on a boat story' you're referring to. It could be about a man's adventure on the boat, like fishing, traveling to different islands, or facing a storm while on the water.
Well, generally speaking, a 'man on a boat story' might involve a man who is on a journey by boat. Maybe he is escaping from something in his life on land, or perhaps he is seeking new opportunities. He could encounter various things during his time on the boat. For example, he might meet interesting people at different ports, or he could have a spiritual awakening while out at sea, looking at the vastness of the ocean and realizing how small he is in the grand scheme of things. There are so many possibilities depending on the context of the story.