When the weight of an object equals the weight of the water displaced (or pushed away) by the object, the object is neutrally buoyant and easy to lift to the surface.

A tanker made of 2.5\times10^3\text{ m}^32.5×103 m32, point, 5, times, 10, start superscript, 3, end superscript, space, m, start superscript, 3, end superscript of steel sank to the bottom of the ocean. The density of steel is approximately 8\times10^3\text{ kg/m}^38×103 kg/m38, times, 10, start superscript, 3, end superscript, space, k, g, slash, m, start superscript, 3, end superscript. The density of seawater is approximately 1\times10^3\text{ kg/m}^31×103 kg/m31, times, 10, start superscript, 3, end superscript, space, k, g, slash, m, start superscript, 3, end superscript. Because gravity is pretty much the same everywhere on earth, the weight of the tanker can be assumed to be approximately equal to its mass.

In kilograms, what total weight of seawater needs to be displaced in order to lift the tanker to the surface?