I had never heard of rogue underwater waves before:

Doomed Indonesian sub may have been hit by powerful underwater wave: report​

"There was nothing that they could do, no time to do anything... if the sub was brought down by such a wave. It likely angled [downward], causing all the crew members to roll down"

How would it manifest itself? A sudden change in pressure? Or would it present an impact force of sorts? @nsaspook

 

I had never heard of rogue underwater waves before:

Doomed Indonesian sub may have been hit by powerful underwater wave: report​

How would it manifest itself? A sudden change in pressure? Or would it present an impact force of sorts? @nsaspook

I think it's like a downdraft in the wake of an airliner. Not really a "wave", more of a localized turbulence.

In my view an "underwater wave" is just audio passing through water.

 

Wouldnt that be on the lines of Tsunami type tectonic plates source at the bottom of the ocean?.
i.e. Large underwater current.

 

I had never heard of rogue underwater waves before:

Doomed Indonesian sub may have been hit by powerful underwater wave: report​

How would it manifest itself? A sudden change in pressure? Or would it present an impact force of sorts? @nsaspook

I've not looked up the facts on the sub so I've no idea what happened to the poor souls. We've been hit by surface solitary ocean waves in that part of the world and seen the underwater effects of internal waves on echo sounders.
https://physicstoday.scitation.org/...of the data gathered,top 200 meters in height.

 

I've not looked up the facts on the sub so I've no idea what happened to the poor souls. We've been hit by surface solitary ocean waves in that part of the world and seen the underwater effects of internal waves on echo sounders.
https://physicstoday.scitation.org/do/10.1063/pt.5.7168/full/#:~:text=Analysis of the data gathered,top 200 meters in height.

That second video is very illustrative, thank you. If that was indeed the case with the sub, it must've been a rather violent event for it to split it in three parts. The crew must've died in an instant, quite possibly crushed by the pressure when the hull broke.

 

That second video is very illustrative, thank you.

Certainly it is!!
When started going at sea I believed that in case of bad weather, subs just needed to go down few meters to feel calm. Later learnt that hell could be everywhere.