Describe the bug
If u sit in the Seamtoh you have a bar in front of your face (only visual). Which is the roof of the Seamoth.

To Reproduce
Steps to reproduce the behavior:
Sit in a Seamoth
and have the mod Shrink installed

Versions
Better Diving: 1.2.3
Forge: 36.0.42
Minecraft: 1.16.5

Other
Singleplayer:
Other mods (that are necessary to produce the bug):
Shrink-1.16.4-1.0.7 - https://www.curseforge.com/minecraft/mc-mods/shrink_

I don't think Shrink is needed to reproduce this issue. My modpack does not include Shrink, but also have the same issue. The sofacopter from CVM also has visual obtrusion(not a bug) when accelerating. I'm now just going to go 3rd person when driving.

Well it has to do something with it, caus I tested it while only having this two mods.

This is due to the player being mounted too high in the seamoth. Go into F5 view to see yourself from the front. It becomes apparent.

This is actually more than a visual bug as the player will still lose air supply - possibly due to the player head sticking out of the seamoth. See image below.

Should be fixed in v1.16.5-1.2.4

Though this bug has nothing to do with you loosing oxygen while inside a seamoth. I guess the power cell of the seamoth is empty. If that is not the case then please create a new issue.