The problem is range. What if the target is far from the water?
I believe they are using old gun barrels for the casings on some of these penetrators.
MOP is capable of penetrating much deeper than stated, and it has fuzing that ensures it goes off at the right time, through some very reinforced WMD bunkers.
http://www.saffm.hq.af.mil/shared/media/document/AFD-090511-083.pdf
Starting on page 179 are the MOP budgeting documents.
All four committees of the congress have signed off on this budget amount.
“What’s the big deal? The 16 inch AP round on a Iowa class Battleship could penetrate 160 feet. Maybe we should build some big guns again?
“
Maybe we shouldn’t have moth-balled our battleships aster having spent hundreds of millions of dollars on modernizing them.
And our F-117s.
And our Blackbird.
And our F-22s.
The list goes on and on.......