Players that are swimming render outside of their hitboxes when looking up or down

The Bug:

Players that are swimming render outside of their hitboxes when looking up or down.

Steps to Reproduce:

1. Enter a deep body of water and enable entity hitboxes by pressing "F3 + B".
2. Begin swimming upwards or downwards and look at your hitbox and your model.
3. Take note as to whether or not players that are swimming render outside of their hitboxes when looking up or down.

Observed Behavior:

Players render outside of their hitboxes.

Expected Behavior:

Players would not render outside of their hitboxes.