Originally Posted by
80ktsClamp
SONAR is soundwaves...
The "pinger" is an acoustic device as well, not RF.
Even VLF only goes down to 20 meters below the surface. Submarines use that for communications when they would come up near the surface. Only ELF frequencies can penetrate down to submarine operating depths. VHF and UHF have far less penetration that is limited to just below the surface.
A 31 year old memory of an event is not nearly as reliable as I thought. We did drop sonobuoys and a device on day 2. Day one was a long involved event from launch off Rescue Alert out of Kadena and reached the AO and ran an electronic creeping line search. The area was a denial zone and each event was extremely provocative on both sides. Thanks to all for helping me clarify my recollection. We did not usually drop sonobouys, though we did carry them, and although searching for objects underwater was not a daily occurrence, we had the capability. The event was so sensitive and fluid, I doubt any of us will ever know the entire story.