Feeling a little dizzy and a burning pressure in his lungs, Aoni knew it was time to try out his next idea. Stopping his downward progression, plugging his nose, and rolling in the water upside down, the Lad reached into his pocket and pulled out a tiny box, one just big enough to cover his mouth.
And that was precisely its purpose. Turning the small object upside down so the water couldn't immediately rush in, Aoni slid the slotted lid off and shoved his lips into the box before inhaling a deep breath of air.
That's right, despite his stupidity, Aoni had actually crafted a means of scuba diving without scuba gear. In a technical sense, all he'd done was craft a small wooden box, make it watertight, and then expand its internal space multiple times, resulting in approximately five or six square feet of usable space.
Then he left it open so that it could fill up with air…that's it, just a tiny empty box filled with air.