If It Is a Tank ...

 ... then I am an alien from planet Zoltar. 

US Marines unveil new tanks that swim and strike with 30mm cannon precision.  The ACV-30 primary armament is a Kongsberg MCT-30 remote turret system armed with the Northrop Grumman Mk44 Bushmaster II 30mm chain gun.

Here it is: 

Pardon my French, but this is no fucking tank. It is essentially an IFV or MFV (M for marines) if anyone is confused.