Although there are practical difficulties, it is possible in principle to float an ocean liner in a few barrels of water. How would you go about doing this?

It is possible to float an ocean liner in a few barrels of water.
According to Archimedes’ principle, the body will float in the water if the weight of the object is less than the weight of the water displaced by the submerged volume of the object. This also shows that the body will float if the density of the water is greater than the density of the object.
Consider the ocean liner is placed in a few barrel of water. Assume that the volume of the water is greater than the total volume of the ocean liner. If the weight of the ocean liner is designed in such a way that it displaces more water, it could float in the few barrel of water. This could be possible if it has large volume made of light materials. Thus, the density of the ocean liner would reduce and could be less than the density of the water. In accordance with Archimedes’ principle, the ocean liner will float in the few barrels of water.