Definition: Nonsubmersible is a concept in physics, specifically relating to the behavior of fluids in which the fluid cannot be made submersion into or out of another fluid. This means that if one fluid enters the body and the other fluid exits through an opening, it will not be able to submerge or rise above the surface of the body due to the viscosity of the fluid. Nonsubmersible fluids are characterized by their high viscosity, which makes them difficult to submerse into. They