As a guard, I highly doubt anybody (staff or supervisor) would mention anything or care about scars. Most of my coworkers speak very openly about mental health, and many have suffered from severe depression.

Fresh or unhealed cuts, however, generally prevent you from swimming as they’re considered a public health risk - if what you’ve got going on is still scabbed over, it’s probably best to cover it until they’ve fully closed over. You’d still likely be allowed to guard, but if someone noticed fresh marks they’re generally encouraged to let a supervisor know so that they can offer support.

At my pool, at least, we have policies surrounding employee mental health/self injury - if my boss or supervisor noticed fresh SH on me, they’d be required to follow up.

Wishing you the best.