I had one of those years ago. It is actually a sail boat. there is a small hole like a cup holder at the front to hold the mast. The slot that is visible in the picture is for the keel. A hand rudder is to attach on the back.
How someone would attempt to fish in it, I dont know.
Ah, the memorys. When I lived in Michigan as a yout, our neighbor had one and the local punks stole it and used it to slide down hills. In the summer in the gravel pit! The gravel pit was an area in the woods that had steep hills that we rode our dirt bikes in. Anyway, the hull got ruined and 1/4 broke off the back. We "rescued" it and used it that winter.
That coming winter/spring was a really strange one. A lot of early thawing flooded huge areas of the forrest behind my friends house. Then it would freeze again and then more thawing. There was a foot of icy cold water over a sheet of ice on the ground. We poled that broken hull all day through there, looked like a white bayou. You had to make sure you put the end of the pole in a crack or hole in the ice otherwise you would be getting wet if it slipped.
My first boat was a Snark! Mine had a plastic coating of some kind. My buddy, who introduced me to sailing, had the plain styrofoam one. It was incredibly durable. Mine came on a 74 VW bug, which VW sold as a promotion - "A Sale On A Sail On A Bug". Came with a roof rack made for the boat. He got his from the Kool cigarettes promotion for 20 empty packs and $20. I never fished out of one, but I learned a lot about sailing and small boat handling. My second boat was a 26 ft. Columbia, which was quite a move up.