There is a regulation that a fish house used for ice fishing must float. What is meant by this?

Specifically, the rule states "Any structure used as a fish house shall be constructed of material that will allow it to float and to be readily removable from the ice at any time." It must be noted however, that only structures used as fish houses that are left unoccupied must meet this requirement. If your fish house is not left on the ice, then this is not a requirement. For those who leave their fish house on the ice, the requirement applies and thus the house must be made of floatable material such as wood and/or spray foam insulation. The Game and Fish Department does not inspect and determine if a fish house will or will not float. However, it’s important to understand that if a fish house breaks through the ice and sinks to the bottom, or is abandoned on a lake and sinks when the ice melts, the owner is not only responsible for retrieving it but may also be fined. Owners of commercially made fish houses should check manufacture’s specifications on whether the structure is made to float.