Plug

Plugs are items found in the Swimming Pool of World Quack Centre. There are four of these to be found in the pool area on the next floor. They are required to block the four drains at the bottom of the pool (one in each corner) to flood the room and access the vent to the elevator shaft.

How to obtain & use
Only Rico can use them. The first two can be found in the corners of the Pool, inside two small shower-like areas.

After you have plugged in the Pool using the first two Plugs by swimming underneath to one of the four corners, the water will raise enough for you to reach the Plug on the diving board at the very end.

After plugging this one in, the water will raise further, allowing you to reach the final Plug on the highest diving board. After this has been inserted, you may access the vent.