A bit of a strange question maybe, but I've recently found a few clips of the 2010 TV series Pacific on youtube which revolves around a number of young Marines deployed to various combat zones in the Pacific Theatre. There's a few good scenes of LVT's being used (both LVT-4's and the turret version armed with the 75mm howitzer (either LVT(A)-4 or LVT(A)-5).
Anyway, I was wondering what is supposed to happen with these kinds of amphibious assault vehicles once they reach the shoreline and the troops disembark. Do they continue the fight and support the infantry with their own weapons or do they return to the landing ships to be reloaded again? Surely a later AAV like the LVTP5 is unsuitable for supporting infantry on land? It would make a rather large and thinly armoured target - probably more so than an AAV7A1. I can imagine the turreted variants would be able to better assist the infantry especially in terrain unsuitable for conventional tanks or other armour.
So what is the typical function of these early Amtracs (and their successor LVTP5) once the initial landing phase is over?