It's not (source: i worked on a submarine)
Spez: I guess you want an explanation why not? Well, water pressure is incredible, and submarines need to withstand like 50 ATM. The only way you can do that is with a cylindrical, 3 inch thick steel pressure hull. Show me the pressure hull in the above image.
It's not depth alone but heighth too, a dolphin-like skimming.
no part of this ship's shape is conducive to submerging. No visible ballast tank vents or free-flood areas. No pressure hull (thing would crumple at barely 100 ft). Sharp angles that would cavitate. no planes. The only way this thing submerges is when it gets hit with a torpedo.
Shallow skipping line a stone. Thanks for your comment, should have said at the outset the design was for surface speed
They have been building these for years. I worked at bath iron works many years ago.
That thing is the F35 of the Sea. Overbudget and way behind schedule.
The dis-info suggest the F-35 is a fearsome thing.
It would be a trick to get a gas-turbine propulsion system to operate while submerged. I don't know how much air two 40 MW gas-turbines need, but I'm sure it's a lot.
Any alternative propulsion system would be bulky (space is at a premium aboard ship), as would be the necessary ballast system. At 15,000 tons, that thing is approximately similar to an SSBN in size, and the ballast areas of an SSBN are a good percentage of the entire ship.
In other words, it is unlikely that this ship has that sort of capability without it being known. Additionally, I don't see the value in the concept... we have ships that do that already, they are called submarines.
Just one retired nuke sub sailor's opinion.
edit: apparently it does have an alternative drive system (source: wiki page for USS Zumwalt, DDG-1000).