A floating unit comprising: a hull having a recess in which a deployable wall is mounted, the wall being movable between a first and a second position; wherein in the first position the wall is enclosed within the hull in the recess; and in the second position the wall at least partly protrudes from the hull, thereby defining a partly enclosed space; and wherein the floating unit further comprises means for supplying air bubbles to the partly enclosed space, the partly enclosed space being configured to constitute an underwater air pocket filled with air bubbles upon supplying the air bubbles from the means for supplying the air bubbles when the floating unit floats in the water with the wall in the second position.