Floaty Jump
Floaty Jump (also known as simply Floaty) is the state that Samus is in when the game applies water physics to her while she is outside of water. As a result, Samus will jump much higher in the air than would otherwise be possible under normal circumstances. This is possible because you can trick the game into thinking that Samus is deeper inside the water than she actually is. There are multiple methods of getting Floaty Jump in the Prime games, and these differ by the room.
While Floaty Jump doesn't have a major use in the three major speedrunning categories, there are still applications for it. For example, there are some Secret Worlds, such as the one in Quarantine Cave, that cannot be done without Floaty Jump.
Technical Overview
In the Metroid Prime series, water is made up of triggers that are placed in the individual rooms. This includes the lava in Magmoor Caverns and the dark water in the Dark Aether regions of Echoes. When Samus interacts with these triggers, multiple values in memory are changed to account for this. Two of these values are relevant for Floaty Jump:
- Fluid Counter: Value that tracks whether or not Samus is currently interacting with a water box. This value can range from 0-3, corresponding with the number of water boxes Samus is interacting with. If this value goes over 3, it will instead go back to 0 and water physics will therefore be disabled. (see also: Abusing Fluid Count)
- Fluid Depth: Value for registering how far inside the water Samus is relative to the surface of the waterbox that you are entering from. Once this value is >1.25, the game applies water physics to Samus. Game does not check where you left a water box from only that your fluid depth is >1.25 when you leave. (see also: Abusing Fluid Depth)
During normal gameplay, the changes to these values only last for as long as Samus is in the water itself. However, if Samus is suddenly transported out of the water, it is possible to get what is known as pre-floaty, which happens because the fluid counter value does not update when this happens.
It is possible to get Floaty Jump in the PAL and Trilogy versions of Prime 1, but the effect will disappear once the room's water box is unloaded. This is because the behavior was changed such that Samus' water physics are tied to the specific water box in this version of the game. This change was first introduced in PAL and then carried over to the Trilogy version of the game.
Pre-Floaty
Pre-floaty is the requisite state for getting Floaty in Prime 1. It happens when Samus' fluid counter value is more than 0 while in the air. When Samus is in pre-floaty, it is possible to touch the edges of a water box and get Floaty Jump as a result. There are two methods of getting pre-floaty:
- Being partially inside a water box at the same time the room removes the water box from existence.
- Being partially inside a water box and then unloading the box while inside of it. This is typically done with Infinite Speed.
Once Samus has pre-floaty, it is possible to get Floaty with one of two methods.
Out of Bounds Method
This is the most common method of obtaining Floaty. Once in pre-floaty, go Out of Bounds and touch the water box. Since Samus is not interacting with the water box normally, the fluid depth value will update as if Samus is already in the water, but will not change once Samus has stopped interacting with the box. Because of this, Samus will have Floaty Jump in the air after interacting with the box.
Overlapping Water Box Method
Once in pre-floaty, go to a room that has a connecting room with another water box. The other water box has to be such that its fluid depth is higher than the one you are entering. In the video below, this is done in the room Frozen Pike. It is possible to carry this increased fluid depth into the box with the lower fluid depth level. This means that when exiting the water box, Samus' fluid depth level will be greater than 1.25, meaning she now has Floaty Jump in the air.
Getting Out of Floaty
Once Samus has Floaty Jump, simply entering a water box like normal is enough to cancel the effects. Once Samus enters the water box, the fluid depth value will update like normal, removing the effects of Floaty. However, the fluid counter value will still be above 0 in the air, meaning that even when entering a water box, Samus will still maintain the pre-floaty state. Despite this, if the route being done requires carrying Floaty through multiple rooms, then it is important to never touch these boxes until it is desired to get rid of Floaty. Floaty will also be lost through any Elevator, Death, or reload from a Save Station. This is because Samus is unloaded losing her fluid count and fluid depth and then reloaded after.
Abusing the Fluid Counter
Inbounds the most water boxes Samus can be in is 3 at any given time. Because of this, if Samus' fluid count were to ever increase from here, it would go back down to 0 instead. By unloading any water box while inside it, you prevent the game from subtracting the water boxes you're currently in. This can allow you to have a fluid counter >0 or as its called, pre-floaty. By stacking pre-floaty multiple times its we can keep adding the fluid counter until it resets back to 0. This can allow samus to have a fluid counter of 0 while she's underwater. This gives Samus normal physics while underwater, known as Pseudo Gravity Suit. This allows acquiring the Energy Tank in Hydro Access Tunnel without Gravity Suit.
Abusing the Fluid Depth
The fluid depth can be abused at the transitions between water boxes. By transitioning back and forth between two adjacent water boxes, it is possible to carry Samus' fluid depth from one water box to the next. This is only possible for one water box at a time and cannot be used to carry a fluid depth through multiple water boxes. This is because transitioning back and forth into the next water box will reset fluid depth you have carried to those respective water box depths. In carrying a high water box value into a low enough water box, Samus can leave the lower water box at a depth value >1.25 giving her floaty jump. By carrying a low water box value into a high enough water box, Samus can have negative water depth value while being underwater. This will give Samus normal physics but only as long as her fluid depth >1.25 or Samus gets a fluid depth >5. If samus gets too high a negative fluid depth the game considers this to be the same as being outside of the water and will set the fluid depth to 0. This will also give Samus normal physics. Both of these versions of Pseudo Gravity Suit will only last as long as Samus is inside that particular water box.
Metroid Prime
List of Rooms That Can Give Pre-Floaty
Metroid Prime 2: Echoes
With current knowledge, there is only one spot to get Floaty Jump in Metroid Prime 2: Echoes. This can happen in the room Dark Torvus Temple, just before the Chykka fight starts, if Samus does not have Light Suit and is standing on the Dark Water when the Chykka fight activates. By doing this, she will have all of the effects of Floaty Jump, including the ability to jump higher than normal. Because the requirements for getting Floaty are so specific, it is only typically used in a couple of niche cases, such as being able to defeat Power Bomb Guardian without the Spider Ball.
Metroid Prime 3: Corruption
TODO