Step 1: Place a boat on a slime block. Make sure you are in 15w41a or later.
Step 2: Wait (if you want). The longer you wait, the higher up you go. Maximum height seems to be directly proportional to time spent waiting.
Step 3: Get in the boat. You should be launched upwards tens or hundreds of blocks. When you bounce on the slime block after coming back down, you will bounce up exactly the same height.
Tested to confirm, but original source: https://www.reddit.com/r/Minecraft/comments/3o9rlr/15w41a_boats_slime_blocks_up_hundreds_of_blocks/
Linked issues
is duplicated by 4
Comments 12
Are they actually duplicates? MC-90307 is caused by air having a deceleration of zero, which makes the boat travel infinitely horizontally. On the other hand, this bug has the boat start on a slime block, and leads to a launch into the air, seemingly prompted by nothing.
Granted, I am not very experienced with Minecraft mechanics, but I'm surprised that this is marked a duplicate.
They both have to do with being pushed into air.
Leaving it open and linking as related instead.
They're both the same thing just being reproduced in different ways. That one gives it momentum using a slime block and the boats collision and this one simply pushes it up into the air.
Confirmed for 15w45a
Confirmed for 15w46a
Confirmed for 15w47a
Confirmed for 15w17c
Elytra launch feature 😛
migrated
Dupe of MC-90307