Minecraft 18w07a, Minecraft 18w07c
Items will repeatedly float to the surface then glitch to be 3-4 blocks below, and resume floating to the surface.
- Go above kelp (all the times I've tried it it has only happened above and in kelp)
- Throw out a variety of items
→ Some will float normally, while some glitch downwards, sometimes once they have reached the surface, sometimes under the water