When a trapped skeleton is activated underwater, the skeletons on horseback seem to be able to move in all cardinal directions at a super speed which doesn't seem natural, including "coasting" for long distances in horizontal directions after moving off the edge of a block.
How to reproduce
Go to an ocean biome and go down to or near the ocean floor
Add some buffs for your convenience:
/effect give @p minecraft:night_vision 9999 1 true
{{ /effect give @p minecraft:water_breathing 9999 1 true}}
{{ /effect give @p minecraft:resistance 9999 100 true}}
/gamemode survival
/summon skeleton_horse ~ ~ ~ {SkeletonTrap:1
}Watch the behaviour of the skeleton horses underwater
Notice how they move extremely quickly, jump up blocks and then ride off them in a horizontal fashion with no immediate downward momentum.
Linked issues
duplicates 1
Comments 1

I think this is a duplicate of MC-129998
Despite my searching you don't always find what you're looking for!