Detective Comics Vol. 1 Issue 663

Knightfall Pt. 10
No Rest For The Wicked

Batman drags Mayor Krol through the flooded Gotham River Tunnel, hoping they can survive. He dives underwater and discovers a possible exit through the tunnel walkway, 30 feet below the surface. Krol is exhausted and afraid, so Batman knocks him unconscious and wraps his cape around him to keep the water out of his airways. He carries Krol underwater, holding his breath until he comes to an exit. Unfortunately the hatch is rusted shut, and only his anger at Bane's manipulations gives him the extra burst of strength he needs to open the hatch before drowning.