Sort of off topic question but does the PPC actually fire under water without causing suicide?
No but be EXTREMELY CAREFUL using it on Clearcut and Marshes. Any kind of vegetation, even a god damn FERN, will cause splash damage.
The shot will usually continue through and hit the target so you don't have to worry about plants far away, but I've been killed MANY A TIME by my face exploding because of this. Something that seriously needs to be fixed.
Also some of the rocks on Sandblasted and Inferno have horrible geometry problems. It'll look like you can easily shoot through a concave surface - instead it's considered part of the rock face and you die.