1,170,347. Submerged tanks. CHICAGO BRIDGE & IRON CO. 12 Dec., 1967 [21 April, 1967], No. 56448/67. Heading E1H. An underwater offshore liquid storage tank floatable to a site for positioning on the floor of a body of water comprises a roofed shell 11 enclosing a volume to which water can be supplied through tubes 38 and from which air can be removed through vent lines 40, and a hollow vessel 10 joined to the roofed shell to which liquid can be supplied for submerging the tank on to the floor, the hollow vessel 10 having buoyancy sufficient to statically float the roofed shell above the floor of the body of water when partially or fully submerged with all air removed from the roofed shell. In the embodiment described the roofed shell has a circular vertical wall 27 at its peripheral edge by which it is anchored to the floor of the body of water.