The AAAV is the advanced follow-on to the AAV-7A.  it features speed comparable to the M1 with amphibious ability comparable to the AAV-7.  These are a partial list of specifications.  
-Hull Design-the AAAV uses a specially formed high speed hull which         allows it to reach unprecidented speeds in the water.       
-Propulsion System-the AAAV uses a incredible 2600hp      MTU/Detroit Diesel turobocharged diesel engine.  It is a self      contained unit which will last at least 9 years and only require      an oil change every 2 years.  It drives a pair of powerful 23in      water jets which can drive it through the water at over 43mph.       The propulsion system is powerful enough that the impeller blades      can 'eat' a 4inch by 4inch log without any damage!  Once on dry      land the AAAV will travel at over 50mph while using only 800hp of      its engine.  
-Retractable Tracks-The AAAV's track system is shrouded to avoid      interfearing in the water flow over the high-speed hull.  On dry      land the AAAV uses the same type of suspension system as the M1        providing excellent mobility.          
-Armor-While it is over 27 feet long 12 feet wide and 10 feet tall The      AAAV uses advanced composite armor to achieve greater armor      protection then the M2A3 Bradley while weighing only 30 tons.  
-Vetronics-The AAAV is fully equipped to operate on the digital      battlefield.  It includes second generation FLIR systems for the       gunner and the driver.  It ties a GPS/moving map display, a combat      identification system, and a digital data-link all tied through 3      SINCGARS jam-proof radios.    
-Armament Package-The AAAV is equipped with a M242 25mm Bushmaster      cannon, 12.7mm machinegun, and 7.62mm machinegun.  There is also a      launcher for the new fire and forget Javelin ATGM.  
-Payload/Range-Each AAAV will transport a 13 man rifle squad and a      heave weapons team for a total of about 18 men + a 3 man crew.       Given this load the AAAV will be capable of swiming over 65nm, or      traveling over 300nm on land.  A typical mission profile would the      AAAV swimming 25nm to shore, moving 100nm to and from the      objective, then swimming 25nm back to the ship.  All in seas up to      10 feet, in the event that the AAAV is overturned it can right      itself automatically in sea states up to level 5.    
The AAAV will enter service in 2006 with 1013 units planed for procurement.  


(text ripped from Tom Clancys 'Marines') good book buy it.  