And to further confuse things apparently the USMC wants to replace the AAV series vehicles with an ACV1.2, a larger variant (13 passengers, better armor, possibly a LAV-25 type turret) of the ACV1.1. The problem is that while the ACV1.1 can handle rivers it can't handle ocean surf, the ACV1.2 will be able to.
https://www.fas.org/sgp/crs/weapons/R42723.pdf
http://breakingdefense.com/2016/09/b...e-for-marines/
As I mentioned elsewhere one of the problems with replacing the AAV series vehicles with ACV's is the USMC will require apx. 25% more sealift then an equivalent sized MEU equipped with AAVs. But more ships will at least make the Gator Navy (the popular term for the amphibious warfare branch of the US Navy) happy.