Reflecting nothing can be as bad as reflecting a big bright 'ping'. Once you get to a certain level of stealth you have to essentially camouflage against an 'em

Reflecting nothing can be as bad as reflecting a big bright 'ping'. Once you get to a certain level of stealth you have to essentially camouflage against an 'empty' background or you become a conspicuous absence. Edit: I'm thinking more about visual camouflage here, though - maybe for sound underwater there's no point at which being quieter becomes a liability?