The General Dynamics MK 46 Mod 1 is a naval gun turret derived from the one developed for the US Marine Corps' Expeditionary Fighting Vehicle (EFV), formerly known as the AAAV. MK 46 features the Mk 44 high velocity 30mm cannon and a second generation thermal day/night sight. The turret is operated remotely and is intended to provide close-in protection for surface ships.

The Mk 46 naval gun turret was selected for the US Navy's LPD 17 San Antonio-class amphibious transport dock ship. The first MK 46 weapon system is expected to achieve operational capability by 2006 onboard USS San Antonio (LPD 17).

In late September 2006 the US Navy awarded General Dynamics Amphibious Systems a $5 million contract for two MK 46 Mod 2 weapon systems. These weapons systems were scheduled for delivery before March 2008.