Drip Drip Cave

Drip Drip Cave is a supposed secret course hidden in Super Mario 64, specifically in the Dire Dire Docks course, found in certain personalized copies of the game. The level is in a large, flooded cave filled with water, with very little spots for air, aside from the very top which has a bit of land. It also gets much more darker the deeper the player swims inside before reaching the bottom, where a sunken ghost ship can be found.

Analysis
When warped to Drip Drip Cave, the player comes out of a hole near the top of the cave. The very top of the cave contains many Goombas and coins to collect, as well as a Metal Cap the player can use to sink to the bottom of the course faster. Inside the water is many Unagis that come out of small holes that attempt to bite the player, as well as various coins and Red Coins for the player to collect.

When the player swims deeper in the cave, the area gets much darker as Boos start appearing in the water, chasing down the player. There are also less coins than near the top of the cave.

Finally, at the bottom of the cave, the entire room is almost pitch-black, with the sunken ghost ship being the only source of light. Swimming inside the ship will bring the player to a flooded area similar to that of inside the ship from Jolly Roger Bay, with many Boos going towards the player, alongside a Star near the bottom of the room.

MISSIONS

 * 1) INSIDE THE GHOST SHIP
 * 2) RED COINS AT THE TOP
 * 3) GHOST HUNT IN THE CAVE
 * 4) METAL MARIO IN THE DEPTHS (Has yet to be collected by a player)
 * 5) UNKNOWN
 * 6) UNKNOWN
 * 7) 100 COIN STAR (Presumably)

Theorizing
Due to how finished looking the course is, players have assumed this stage was cut late into development. The reason for it is unknown, though players assume it could be due to it's difficulty. Due to how deep the water is, and the fact that there is less and less coins the deeper the player goes, it is very easy for the player to drown if they don't ration their coins properly. It could've also been cut due to sharing too many similarities to Jolly Roger Bay, and the fact that there were already 2 water-themed courses in the game.