The Water Realm is entered underwater.
Drivers are sunk to a jellyfish-like structure that grows an air bubble around the top to enclose the cars. The bottom of the structure opens to let the drivers fall to the track below. The track is encased in a glass tube underwater, and periodically has holes in it, which do not flood the tube. Drivers can hydroplane over the surface to stay above the water and on the track. Large skeleton fish that resemble anglar fish swim freely in the water surrounding the tube, and sometimes through the breaks in it. There are multiple splits in the track and sometimes it is surrounded by colorful sealife such as coral. Eventually the track leads upwards onto the surface and loses the glass tube and has drivers manuver around seaside cliffs. The track dips and turns so that the surface is underwater, and drivers need to hydroplane over the water correctly or risk crashing into the rocks.
Deezel "Porkchop" Riggs
Is the first time that a teku use a accelecharger in a realm
Power Rage & Jack Hammer are the two cars that the humans lose
This is when the humans figure out you can go to drone headquaters in or attatched to a drone car, and that using the EDR (Emergency Driver Return) will send you out of the portal at the speed you're going, since this was also the first Realm the EDR was used (by Porkchop.)
A shark appears on the card from the card game, but never appeared in the movie (only angler fish and manta rays)