Fluidization works by pumping a fluid into a denser solid like material, and therefore turning the solid into a slurry or more fluid like substance . The fluidizer pumps water into the tight packed sands on the seafloor. The packed sand then loosens and as the water starts to get between the particles, the particles begin to separate. This creates a much more fluid layer of sand. This fluid layer allows the other Fluidizer systems to move the slurry.
Cespedes, Morgan; Christiansen, Ryan; Chen, Shouyu; Clancy, Phillip; Schifferl, Eric; Winter, Nathen; and Zajac, Adam, "The Fluidizer (Sand Management Device) 2016" (2016). Ocean Engineering and Marine Sciences Student Publications. 35.