It doesn't surprise most of the sightings are from people who spend all day and night looking down into the water....
The sub is interesting, catching it on sonar...the equivalent of spotting a bogie on radar.
I agree.
There have been other USO's caught on sonar etc. usually moving at "impossible" underwater speeds.
And there was at least one playing cat and mouse around--under--both sides--fore & aft of a huge carrier.
Some have been visually and radar/sonar seen entering and exiting the water. Occasionally one will be seen exiting the water only to go back in shortly thereafter--or vice versa.
There have also been reports of a USO playing head on collision games with a sub much as those in the air have played with airliners and military jets.
Then there are the long standing rumors of undersea USO bases.
The "impossible" speeds under water could involve a number of things, imho--though I'm far from a physicist. The ones doing fantastic things in the air--some say by some sort of ion laminar flow or some such. Don't know how well that would work under water.
Others contend that the craft utilize other dimensional aspects to play games with "conventional" physics.
Others say that our conventional physics is flawed. Ben Rich--retired head of Lockheed Skunk Works noted that Einstein had at least one error in the equation--and that we know what it was and it has been corrected now.
I just think we have hardly cracked the door on super exotic "impossible" tech that's going to surface in the next few years as we ramp up to and go through WW3.