The game starts to render things as if the player were in water before his/her eyeline actually meets the water. This makes swimming on top of water very annoying because the sky keeps glitching.
MC-132152
Water vision before water meets the eyeline
Resolved
Duplicate
2
Bogdan Barbu
(Unassigned)
Unconfirmed
Minecraft 1.13-pre4
Retrieved
To avoid this you can angle the camera more upwards. You wont exit the swimming animation as long as you aren't holding your jump key as well (spacebar).