The BILS filled with saline water submerged and sunk to the ground, but remained uprigth as there was an air bubble enclosed. This can be seen on the picture. Enclosing some air may be an option to control the position of the BILS, in a similar way as it is done in submarines.
When removing the air bubbles and when increasing the concentration of salt, the BILS is sinking to the ground and going again in horizontal position. A similar effect as seen for the warm BILS which isurfaces and goes in a horizpontal position.
Not so easy to get it up again....