Large black artifacts appear when looking at far away chunks underwater, this also applies when near the water level such that some part of the camera is not obscured by water.

I am using Iris v1.8.5 on Minecraft 1.21.4 on Windows 10, using an RX 7900 GRE with the latest Radeon Adrenalin 24.12.1 drivers.

I'm having trouble reproducing the bug. Shortly before your report, the shader was updated due to a similar issue. Please make sure you are using the latest version (9.1c). Are there any mods besides the shaders? Does the bug occur at a specific draw distance? Are there any draw distances where the problem doesn't appear? It's true that I can't test it with an AMD GPU, and that might be the issue. Does changing the driver version affect the situation?

If you can verify any of this, it would be a great help. Thanks.

This issue is solved as of 9.1c