When you go on water lake, there is two light level.
I don't know if it's a bug or a feature so i report
MC-47644
Displaying water bug
Resolved
Duplicate
0
It seems that the light levels drop by 3 depending on far down in the ocean you are.
Also, on replication, it appears the underwater fog affect disappears between the light levels of 6-9 (in the ocean) and the position of the player's arm is further away from the screen (as if the player was on land).
I think the light levels may be a feature; however, the transition between these light levels+loss of water fog/effect may actually be a bug.
This 'bug' also features on the Windows version (Java 64-bit)