[mazda77]

Our submarines and sonar buoys can hear a mouse fart for miles, point it’s location and tell you what it had to eat.

[don-o]

Would it be safe to assume that we have had our ears on in that locale?

[Lower Deck]

Our submarines and sonar buoys can hear a mouse fart for miles, point it’s location and tell you what it had to eat.

It's a little more difficult than that. How far you can detect a target through passive means depends on water conditions, temperature, salinity, depth, biologics in the area, signal strength, so forth.