Portable sonar for freediving

[WeRtheOcean]

I was a sonar operator in the Navy. I can tell you that sonar is not an exact science. Even our fathometer could give fluctuating readings over what seemed impossibly short distances for such big changes in bottom topography. And there was also the deep scattering layer to beware of.

The disto won't work in very high humidity "misty" conditions, there's too much scattering of the light beam. Same issue happens underwater, its not possible to use lasers due to refraction, diffusion, and beam scatter.

Sound beams face the same limitations. Under some sea conditions, our sonar data wasn't worth a crap. Seasonal changes could make the same sea "clear as mud" that was at other times excellent "visibility."

 

[rjack321]

I was a sonar operator in the Navy. I can tell you that sonar is not an exact science. Even our fathometer could give fluctuating readings over what seemed impossibly short distances for such big changes in bottom topography. And there was also the deep scattering layer to beware of.



Sound beams face the same limitations. Under some sea conditions, our sonar data wasn't worth a crap. Seasonal changes could make the same sea "clear as mud" that was at other times excellent "visibility."

Yep, at least with this handheld unit the OP posted the beam angle is fairly wide too which is counterproductive for cave surveying. By the time the wall you want to measure is far enough away for you to want a remote measuring device (10m+) the beam width is pretty wide and inconsistent unless the wall is basically flat.

I don't exactly know how it could be useful for freediving in the ocean. I guess if you were on the surface and wanted to know how deep it was because you might be close to your max freediving depth. It could advise you to move shallower or that you are in a depth that is fun for you.