C162 Half a Duckling

Shaang Peiyan submerged the device into the water, where it lit up with a red dot, bobbing up and down as it awaited instructions. He projected an image from his watch onto the water's surface, revealing what the little gadget was seeing underwater to both of them.

Xiaodu maneuvered the detector along the wall, and sure enough, found a cluster of seepage holes on the innermost wall