So I was watching a video on a new Russian submarine being referred to as the Black Hole, due to it’s uncanny ability to avoid detection using typical underwater sound related methods. So this got me to thinking, isn’t the use of sound as a mechanism to find something underwater so 1945? What about using something a tad more modern like say laser? Couldn’t you theoretically use a laser (in a wide beam) to scan a section of water and when it detected a blank space, where no water existed, it could then narrow it’s beams to render the void into a 3d model or sorts? Water good, no water……nope fish. Water good, no water….submarine BAD. Also this sort of scanning might enable the scanner to not reveal their location or even that fact that they were scanning in the first place.
Thinking more, I wonder how well lasers work under water? Maybe the final solution wouldn’t involve the use of lasers at all, but instead some other technology.