The sink is also part of Polo’s estate. He gave it to his little sibling, Dawn, so that they could practice how to swim before the Slipstream competition. As a practice area, the Sink is just a small rectangle track that you swim around a lot.

There are some forks, plates and sponges on the track, you can go between them for a quick shortcut if you’re small enough. You’ll be racing around this track 7 times, and you can do it in either direction, so there is a lot of chaos when there are multiple bubbles moving at once. Be careful not to be bumped around too much!