Notice: I do not claim ownership of this mod, I am merely redistributing it for my CurseForge modpack, as I could not find it released on CF.
Availible for 1.7.10 Forge! 
📖 About:
Aqua Acrobatics is a direct port of the new movement features added in modern versions of Minecraft, most notably the swimming mechanic.
📚 Contents:
Swimming is triggered when the player starts to sprint while underwater. Both the increase in speed as well as the fancy animation make traversing bodies of water a lot more fun.
The player height when Sneaking has been decreased to 1.5 instead of 1.65 blocks. Through this change it has been made possible to sneak through smaller gaps.
The Player Hitbox is forced to stay in a smaller state if there isn't enough space available. This means you can no longer stop sneaking by letting go of the key if you are in a tight area. But it also enables you to e. g. crawl through one block high holes.
Changes to the Eye Level are really smooth. This is achieved by backporting the fix for MC-48401.
Aqua Acrobatics also backports the new Water Colors And Fog from the Update Aquatic. The colors can be customized in the config. Support for Biomes O' Plenty is included out of the box.
Additionally there are also some tweaks unrelated to swimming included. Some of them being: the air meter no longer refills immediately after reaching the surface, easier elytra takeoff like in Minecraft 1.15 and onwards, sideways sprinting, and sprinting not being activated by double tapping. Some tweaks are disabled by default.
Furthermore Aqua Acrobatics has great compatibility with a lot of well known mods such as Mo' Bends by Iwoplaza, Morph by iChun, More Player Models by Noppes, Wings by Pau101, and ArtemisLib by Camellias.
📷 Media:
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| | The player swimming towards the camera | |Fancy swimming animation from behind | | | | 
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| | When sneaking the player perfectly fits into a 1.5 blocks gap | |Player pose will adjust depending on the space available | | | | 
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| | The player sneaking through a tight space | |The player is forced into sneaking pose by an extending piston | | | | 
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| | Push Player Out Of Blocks "Standard" option | |Push Player Out Of Blocks "Approximate" option | | | | 
| | | | Push Player Out Of Blocks "Exact" option | | | | |
✏️ Notes:
A mod such as MixinBootstrap or Mixin 0.7-0.8 Compatibility is required for providing the Mixin framework used by Aqua Acrobatics. Otherwise this mod will fail to load.
In addition to one of the above mods, consider installing MixinBooter as well. With this mod installed Aqua Acrobatics can also patch some other mods to help improve compatibility.
(1.12.2, unknown with 1.7.10!):
While maintaining great compatibility with most mods, Aqua Acrobatics is fundamentally incompatible with some mods changing the same game mechanics. So far Idō by Bagu Chan, and Better Sprinting by Chylex are known.
Thicc Entities by Wiresegal is incompatible but you can use the updated fork Entifier instead.
Aqua Acrobatics has compatibility issues with TickCentral (used by LagGoggles and Tiquality), but there is a workaround available here.
