Crawfish boats... crawfish, are like tiny lobsters, that live in swamps, marshes, and ponds and are trapped like minnows.

These little crafts, heirs to the old Cajun swamp-going boats but with the benefit of generations of creativity and modern materials, are constructed both to glide along the top of a flooded field and to ride easily along dry roads, even going along the side of the highway toward the next crawfish field. No two of these boats are exactly alike because they’re not mass-produced in factories. Instead, they’re just made in the area where they’re needed by a handful of men who know how to build machines.

An engine operates a hydraulic pump and motor to propel a metal wheel that extends beyond the boat. Metal cleats are welded to the wheel, which is mounted to the rear to push the boat in shallow water. The hydraulic steering can be operated with foot pedals, leaving the driver’s hands free to empty and rebait traps.

http://quirkswelding.com/5trackboat.html

there is even a good book about them

The Amazing Crawfish Boat chronicles the development of an amphibious boat that transformed the Louisiana prairies into alternating fields of aquaculture and agriculture. In seeking to understand how such a machine came into being, John Laudun describes the ideas and traditions that have long been a part of the Louisiana landscape and how they converged at a particular moment in time to create a new economic opportunity for both the rice farmers who used them and the fabricators who made them.

https://soundcloud.com/johnlaudun/sets/the-amazing-crawfish-boat
https://www.amazon.com/Amazing-Crawfish-Folklore-Studies-Multicultural/dp/1496804201
http://thewandererschuckandkate.blogspot.com/2011/04/cajun-tale.html