Infinite upward elytra flight is possible due to a potential oversight with water and not resetting upward velocity at world height.
This bug affects Minecraft Java Edition versions 1.13 pre9 through 19w40a.
- Place at least one water source at the max world height and add some blocks adjacent to it.
- Submerge yourself in said water; it doesn't need to be two blocks deep, you could just put your lower half in it.
- Hold the jump key to swim up out of the water onto the adjacent blocks. At this point, you should notice that, if you jump, you get a sort of slow-falling effect.
- Put on an Elytra, then jump and activate the Elytra.
- Look in a mostly horizontal direction and continue to hold jump. You should see that you continue to go upwards. If you go in 3rd person mode, this is made even more obvious.
- If you set your pitch to 35.4 (or other close values to that) either manually or by doing /tp @s ~ ~ ~ ~ 35.4 and continue to hold jump, you will notice that, eventually, you can completely stop mid-air.
- You need to be above the world height in order to do this. If you descend below it, it will stop working.
- It does use elytra durability.
- This also works with upwards bubble columns, but not with lava, slime blocks, jumping normally, taking knockback damage, or any other ways of gaining velocity that we have tested.
- Thank you to Saltswimmer, BOAAY, and Jetstreamjoejoe for helping test things!