To provide a simple method that requires less work, time and cost than methods of the prior art by adjusting the buoyancy (apparent weight) of a box by means of bubbles.

In this method of adjusting the buoyancy of a box 1 temporarily installed on the bottom of water, for resisting turbulence through adjustment of the buoyancy of the box 1, a bubble-generating hose 3 having a number of pores therein is installed on the bottom of water corresponding to the temporarily installed position of the box 1. The interval between the casing 1 and the bubble-generating hose 3 is maintained and the casing 1 is temporarily installed on the bottom of water. Gas is fed into the bubble-generating hose 3 to generate bubbles (a) so as to adjust the buoyancy of the box 1.