Boo Lake is the second Flower Cup course in Mario Kart: Super Circuit. It is, unlike the name would imply, a pier with a lot of gaps, like the Ghost Valley courses from Super Mario Kart. Boo Lake contains a considerable amount of Coins and Item Boxes. There are Boos which hold lanterns on this course, which are very helpful. If the player falls off of the track, contrary to what the name says, they do not fall into water and instead into a pit. There is a bridge that flickers, making it hard to see on the part where the path splits around a hole with the bump on it, to the right of this area.
The race starts out on a long, straight wooden road that eventually leads to a turn to the right. The turn will lead the player into a boost panel and a bump that makes the player bump up. The result of the effect is that the player crosses a large pit, in which they may fall into if they decide to swerve or bump into an opponent. In this small platform, there is another boost panel and bump that will serve the same function as before. There is a boost panel on the left of the platform to fly further. After that, there is an option to take a boost panel to the right, but in 150cc mode, the option to take that is inaccessible unless the player slows down and backs up. After the boost panel is a sharp turn right, which leads into another area.
The path splits and rejoins in this area of the track. There is a bump over a pit, in between the splitting path. The player may successfully fly over the pit if they use a Mushroom to boost and fly far with the bump. After this part is a slow turn to the right and a U-turn to the right, which leads to a straight road, with some Boos carrying lanterns to light up some areas. The Boos will laugh at the player if they happen to cross underneath one, but it will not do anything else to help or hinder the player. After this straight path is a U-turn to the left, which is not very sharp and could be easily cleared without bumping into any walls.
After the U-turn is a slight curve to the left, which has a lot of bumps for the player to slightly get bumped up in the air. After turning to the right, the player arrives at the area where the finish line is. Before the finish line, there are several bumps; some that make the player fly over a very small pit in the left and right part of the track.
There are two shortcuts that the player can take. The first is quite short and narrow, and comes directly before the first small branching in the path. It is extremely hard to see, and resembles a ladder. Due to how easy it is to fall off and the small amount of time gained by using it successfully, it is an extremely risky path to take. The second is after the straight road with some Boos holding lanterns to light up the night. After the last Boo, the player may notice a narrow bridge to the left of their side, just before the U-turn. The player may proceed to cross the bridge to cut time, but it is very easy to fall off due to the narrowness of the bridge. However, it is nowhere near as narrow as the first, and is included on the map.
- Part of this course's music is a remix of the music used for the Ghost Valley courses from Super Mario Kart.
- This course shares the same music as Broken Pier.