Aquarium Swim
If you are in the aquarium level and looking for "swim," look behind the green plant that is directly past the castle. You will see the world "swim."
Aquarium Dice
The first die in the aquarium level is located by the race start pillar. Once you have found the first one, look toward the middle of the tank and you will notice a bridge. The second die is located directly under that bridge. The third and final die is on the ledge where the black eel is.
Aquarium Brush
To find the brush in the aquarium level, first find the fish tank. Once you have located the fish tank, look at the area of the tank near the fish food. The brush is right in front of that area.
Aquarium Skate
The skate in the aquarium is difficult to find because doesn't really resemble a skate. However, if you are facing toward the wall, it is on the left side near the front. Look in between the two shells that are on the bottom in front of the column.