Abstract: Disclosed is a flotation mattress comprising (a) a planar, flexible bag (10) adapted to hold water during use of the mattress, (b) a hollow, annular compartment (12) surrounding the bag (10) in the plane of the bag, the compartment (12) being collapsible in the direction perpendicular to the plane of the bag (10), (c) a plurality of springs (14, 42, 56) disposed in the compartment (12) with their axes of resiliency perpendicular to the plane of the bag (10), the springs (14, 42, 56) biasing the compartment (12) towards its uncollapsed position, and (d) means (20, 34, 36, 38) for maintaining the horizontal stability of the planar, flexible bag (10) while the mattress is in use.

Abstract: Disclosed is a flotation mattress comprising (a) a planar, flexible bag (10) adapted to hold water during use of the mattress, (b) a hollow, annular compartment (12) surrounding the bag (10) in the plane of the bag, the compartment (12) being collapsible in the direction perpendicular to the plane of the bag (10), and (c) a plurality of springs (14, 42, 56) disposed in the compartment (12) with their axes of resiliency perpendicular to the plane of the bag (10), the springs (14, 42, 56) biasing the compartment (12) towards its uncollapsed position, and (d) means (20, 34, 36, 38) for maintaining the horizontal stability of the planar, flexible bag (10) while the mattress is in use.